firefight raging, both sides furiously fighting.. in walk a lonely scared water melon.. both sides cease fire look to one another then to the melon.. (will Defoe shouts boondock THERE WAS A FIREFIGHT) both sides proceed to shoot the melon to shreds and call it a day
3:33 *M193* through a SP1, 20'', 1:12 twist 6:14 *M193* through an A2, 20'', 1:7 twist 8:32 *M855* through the A2 10:38 *M855* through a M4, 14.5'', 1:7 twist 12:42 *M193* through the M4 All above used watermelons 15:28 *M193* through the SP1, meat target
While at the rifle range in Fort Dix, 1973…A Drill Sergeant told our platoon that if you made a shot with our 20” 1/12” M-16 (55 grain ball) and hit the enemy in the back of the head, his face would come off like a Halloween Mask. I never forgot that.
No, Eugene Stoner was the principal designer of the AR but there were other entities involved with the development of the 5.56mm cartridge and the twist rate in the barrel, Stoner didn't design it all himself down to the last little detail. And this test isn't exactly the best way to evaluate the bullet's affect on the human body, the watermelon and human lungs may have similar amounts of water in them but the watermelon is solid and lungs are full of air, also different organs have different densities and even then you've got solid bone coming into play, ballistic gelatin isn't a very good representation either but it's cheap and provides a repeatable testing parameter so that's why it's used so much in the industry. Furthermore the results might have been exactly the same had they switched watermelons, you'd really have to shoot batches of them and get the average of each one for any kind of serious comparison. Videos like this are good for entertainment but they're not really proof of anything, he pretty much says that at several points in the video.
Hey since we are talking about these details, just in case anyone is as fascinated as I am with the evolution of this rifle/platform, @SmallArmsSolutions has a great deal of knowledge and history on it in his videos. I definitely learned a lot from him! Thanks!
@@E_Legal_Alien I've wondered about that as well. That was 223 fuji at very close quarters. I think it was 7ft roughly if I'm not mistaken. So non hollowpoint at close range still did that to his arm. And ppl say 223/556 isn't enough? Can someone explain that to me please
The first time I ever saw an AR-15, I was about ten years old (54 years ago), when I was watching my neighbor shoot his into a creek bank from about 100 yards away. He was shooting uphill from the targets which were mostly tin cans. One I remember in particular was a can that the bullet hit directly on the lip of the can, which was apparently laying on its side. You could see where the bullet impacted the thick metal ring at the top of the can, and literally opened the side of the can like it might have done to one that was unopened or maybe one that was filled with water. I knew at that moment that this was one bad ass rifle!
I remember watching his arm turning into a puff of red spray on live stream..He got the Kyle Rittenhouse treatment. The other guy laid down and went to sleep instantly.
5.56 effectiveness is only debatable outside of 400 yards. inside 100 a 64-124gr bullet that leaves a muzzle at 2,600-3,000 fps will put you down easily. Barring any freak circumstances (Miami shootout).
@@thebushbunker What do you have? 1-in-14s were designed for 55grs, and 1-in-12s for 55gr tracers. A 1-in-9 should be sufficient for 62s, even if most of those are longer than normal due to the lighter penetrator of the M855.
When I was in boot camp in 1971 we had the slab sided M-16's ( No forward assist) with the skinny barrels and three prong flash hide . Infantry AIT we had the forward assist rifles with a bird cage flash hider. Late I went back to Ft. Polk as a range officer for BCT and infantry AIT. We had time on our hands so some of us shot a lot and I found the the 55gr ball ammo sometimes didn't penetrate both sides of a 55 gallon drum. The bullet broke up on the other side of the barrel you would see some exit holes that looked like it was hit with bird shot. Same with ammo cans filled with water and sometimes there was no damage at all to the exit side of the ammo can. We used to shoot water filled ammo cans to show boots what the M-16 did on impact and I wish I had some of those un-shot cans now.
I just got done reading something that said the 55gr. tended to fragment on impact, which is what they wanted, but it was impossible to predict where the fragmentation would occur because it wasn't consistent. So, they moved to the heavier bullet to get away from the fragmentation concept.
@lisar3006 - Back in the 1950s, when Eugene Stoner and his team were working on the light automatic rifle project, the army specified that the weapon be chambered in .22-caliber, so they had to meet the lethality requirements in another manner than by using the traditional answer of increasing bullet mass. The wounding capability was to be equivalent to or better than the .30-cal. Carbine 110-gr. round. Stoner's solution was to pump up muzzle velocity, and also to take advantage of the inherent yaw of light-weight projectiles at high velocities. This was done by making the M193 FMJ/Ball round with a crimping groove or cannelure. At impact velocities at or above around 2600 fps, the slug would shatter into several pieces, each of which generated its own wound channel or track, thereby mimicking the performance of a HP or expanding bullet without actually being one. This is when encountering a soft target; when hitting something more substantial, the bullet breaks up even easier - as you saw. The M855/SS109 62-grain projectile was designed by NATO. In order to enhance its effectiveness against barriers, it was given a steel cup or core inside its lead matrix to add weight and momentum down-range such that it would penetrate a standard Warsaw Pact metal helmet at 500m. Not truly armor-piercing, this round was termed "enhanced penetration" instead. The improved penetrative ability came at something of a cost, however, in that the new 62-grain load did not always fragment reliably in the terminal phase of flight, as the older 55-grain load was designed to do. Given the dependence of the 5.56x45mm NATO round - whether in 55-grain or 62-grain - upon high MV for optimal performance, it should come as no surprise that inconsistencies began to be encountered as barrel lengths were shortened during the 1990s. These shortcomings led to the development of new loads which performed better at lower velocities and also against barriers.
Something to consider is that not all M193 is the same. IMI M193 goes well over 3000 fps out of a 16" barrel and is around 100 fps faster than other brands at 16". Some chrono results indicate the difference in velocity is negligible out of the shorter barrels (10.5" and under). As long as the round is above 2200-2300fps when it hits the target, it'll do 5.56 things. Longer barrels at range really are comparable to shorter barrels at close quarters.
@@keres993 Yes, but "5.56 things" is very vague. 5.56 may impart hydrostatic shock above 2200fps, but the difference in damage done at that velocity vs something like 3250fps (20" velocity) is very dramatic. In this video we can see what a 300ish fps difference makes when it comes to terminal effects, so it's obvious that barrels under 14.5 would be even more underwhelming.
@Lost_Achaean True, but those same modern loads produce even more extremely damaging wound channels out of 20" barrels. There is no replacement for velocity.
My Dad had friends in the Agency in the very early days of Vietnam 61-62 and the then AR-15 already had a reputation of massive damage, and that was with the 1-14 twist. It would be interesting to see a 1-14 vs 1-12 comparison. Great video, thanks!
@@Yugetubes Gunnys gone and not breaking his boot off in youguns asses anymore and look where we're at... kids that dont know if they're a boy or girl are rallying support for commies and burning cities. Pitiful lol
My dad served in the Corps back in the early 80s and was issued an A1. Growing up he told us stories of how you could shoot a man in the chest and the round would exit through the guys leg. Never had the same experience during my time in but this test lends some creedence to what he told us.
@@taproom113 well I'm pretty sure that's where the stories came from mostly. Especially considering that after they switched to 1/7 and m855 the stabilization was significantly different and more effective compared to 193 and 1/12
My brother is a physician with many years of trauma care experience, and he related to me years ago that bullets tend to ricochet around quite a lot inside the body, if they don't pass cleanly through, and encounter bone. Sometimes, if the slug is tough-enough and possesses sufficient kinetic energy, it passes through bone, but often times it fractures it and/or bounces off. That's how someone shot in the upper body can have an exit wound a long ways away, even well down an extremity. I don't remember how the subject came up; we don't habitually sit around talking about such gruesome stuff.... maybe it had been a tough stretch in the hospital treating a lot of GSWs after a gang war or something like that, and he needed to blow off some steam or something.
And don't forget the new and improved fleece bullet stop. Perhaps instead of the fleece, we can stop the projectiles with inane run-on sentences filled with anti American sentiment.
@Leslie Dodds 70% of us are still not overweight. I'm a 6' 2" and 250 lb vetran. Not overweight. Thankfully having served overseas I know most brits are awesome people. Not elitists blowhards. As for the other bit. Religion should generally be kept out of it. I'm southern Baptist. Here's hoping whatever bugs up you tail finds it's way to a new home.
It would be interesting to see this test at 200 yards. The reason I say this is that recently I was reading Hatchers Notebook and they conducted a test where they shot M2 Ball into a wood (oak IIRC) target at close range (maybe 25 yards) and the bullets yawed and had little penetration. Then they shot the same type of targets at 200 yards and had straight line penetration of around16". Their conclusion was that it takes some distance for a bullet to completely stabilize. I found that to be most interesting and wonder if that is common to all bullet diameters. Nice test, well done, and fun to watch.
Depends on twist rate, barrel condition, bullet length, to some extent barrel length and temperature. Yaw damping takes a bit of distance no matter what. Night fires with M16A1 with tracer was spectacular with different rifles showing slight differences in the yaw damping as seen from the wobble in the trace. Sometimes it would wobble close then far out as they destabilized again. Tracers lit off bright about 15 meters out at a minimum.
"Short-range" instability is actually normal. All of the forces that act on a bullet after it leaves the muzzle take time to "balance". At short ranges, rifle bullets spiral around the actual / nominal" trajectory. The better the barrel, especially the last couple of inches and MOST especially, the "squareness" of the crown and the better the bullet; the smaller that PRECESSION is. Exterior ballistics is a weird and wonderful field of study.
Re: "Then they shot the same type of targets at 200 yards and had straight line penetration of around16". Their conclusion was that it takes some distance for a bullet to completely stabilize." In the vernacular of firearms types, the distance the bullet takes to sort itself out gyroscopically and become stable, is known as "when the bullet 'falls asleep,'" and is thereafter stable in flight for a fairly good distance. That accounts for the difference in the terminal effects of that M2 Ball described in General Hatcher's notes. The process of gyroscopic instability and stability can be seen in a rapidly-spinning top, which is wobbly and somewhat unstable at the start, but becomes stable and regular in its rotation and orientation within a short interval of a few seconds. It's the same principle, really.
I've seen some videos that explain that there's a velocity threshold that will cause a spitzer bullet yaw in a target vs not. At close range it's going so fast that the yawing is more likely to happen.
It’s almost like the developers of the rifles put a fair amount of research into the weapons platforms they designed. Lots of things I haven’t really put any thought into before. Well done.
I would love to see the difference at longer ranges, 75 & 100 yards. Maybe even with different caliber AR15 rifles. 6.5mm Grendel? I do love Paul Harrell's videos. He always reminds me of a college professor giving a lecture.
I’m gonna compliment you on having the knowledge to shoot from a sitting position because as Grandmaster Jay says that rifle will knock you on your ass. My buddy and I have our version of the Paul Harrell meat target that we use a Carhartt barn coat for outer covering (New England meat target) and I wasn’t there but he tested a 14.5, 16 and 20” barrel and he said he was surprised at how anemic the 14.5” performed and that the 16” was much closer to the 20” than the 14.5” but the 16 was also a 1/8 twist not 1/7. Thanks for the vid and hope your shoulders ok after absorbing 6 monster 5.56 discharges
I really hope you are being sarcastic about 5.56 recoil. Compared to the 7.62x51 in the M-14 or the 30-06 in the M1 the 5.56 is anemic. 5.56 =3.36 ft lbs 7.62x51 =18 ft lbs 30-06 = 21 ft lbs.
john kendall I’m referring to Grandmaster Jay the leader of NFAC posting that video saying the AR15 is a bull pup rifle with recoil that will knock you on your ass. The 5.56 is a 22 and shoots as such but his video where he was expounding his great knowledge was laughable and that’s what I was referring to. He was also posing with a Clinton ban era AR and claiming he bought it in Germany in 1990.
This has to be one of the most refreshingly entertaining gun videos on your channel! Not saying that your other videos are bad, but this was a very welcome break in your regular postings.
As opposed to the 62 grainer which some claim will keyhole from a 1/12, or the 55 grain in the 1/7 which some claim is too fast for 55 grain (yet to find evidence of this 'overstablization' causing problems, but it's safe to say it's certainly not ideal), the 1/9 would put both the 62 grain and the 55 grain in the 'green range' of stabilization according to lots of bullet length/BC/velocity charts. So as far as aerodynamics is concerned, either is quite excellent. Wouldn't trust the M855 for a defensive role, though. It's too velocity dependent for its primary wounding mechanism and I bet it'd be just a bit too temperamental from a 16" barrel in that respect.
@@angry_zergling keep in mind that m855 shoots well out of faster twist rates because the bullet itself is considerably longer than most other in-class 62gr bullets. I’ve heard people compare their length to that of a more typical 69 grain round
@@Turtletanks Would make since as it's part steel and steel is lighter than lead. I'm not sure if it'd be that big of an effect, though. I know monolithic copper bullets of a given weight are a big difference (62 TSX and Hornady 75 HPBT are both .942 for example), but I'm not sure if replacing a bit of lead with a bit of steal in such a small bullet would mess with its OAL too much. EDIT: Just realized I could just, y'know, look up the length of an M855 instead of just give a hunch. Doy. Ahem: M855 is .907. 62 Grain FMJ BT is .813. 69 grain BT is .913. (Note: Made sure I was comparing apples to apples here; since M855 is a FMJ, boat-tail, ball round its compared against the same thing - measurements of hollow points or ballistic tips or OTMs or bullets that aren't boat tailed can be a lot longer or shorter and not good to compare even when they're the same weight and construction.) So you were right and I was wrong. M855 from IMI at .907 is very close to a 69 grain similarly shaped bullet from Barnes. Hadn't thought it'd be that significant, but it is. Interesting, 'cause I've heard of some 1:9 twists failing to stabilize 69 grainers but NEVER heard of any failing to stabilize M855. Could have something to do with the type, though - OTM bullets are a lot longer than 'ball' rounds of the same weight and that could explain it.
@@angry_zergling thanks for giving actual numbers, I was only using previous conjecture for the weight comparison but yeah, m855 is a long bullet in comparison to, say, a standard FMJ 5.56 62gr. One issue that m855 encounters though across the board is that because the round isn’t uniform, as in the steel penetrator isn’t 100% uniform with the rest of the round, it tends to have somewhat more open groups regardless of your twist rate, or at least that’s what I’ve discerned from a small amount of research into the subject. Not really a huge deal unless you’re shooting significantly over 2 MOA, which is about as accurate as military spec equipment could reasonably expected to perform (it isn’t your 77gr Sierra match kings, that’s for sure). But people who claim 1:7 is going to “overstabilize” an m855 round usually aren’t aware of the actual construction and length of the bullet itself, and as of yet the only supporting arguments against a faster rate of twist are that A) the reason the 1:7 twist was adopted was to stabilize the long, heavy tracer rounds that the US military issues and B) conjecture that a bullet will not fly properly through the air when the ROT is too fast I mean frankly I don’t know whether people expect precision performance out of a standard military load but even if you wanted to go 300 or more meters with an AR, you are relegated to heavier bullet weights anyways, and thus would probably want a 1:7 twist.
To sum up: M193 works best in a 20 inch, 1/12 twist barrel (absoluteky devastating), still reasonably effective out of a 1/7 twist barrel of the same length. M855 is absolutely devastating out of a 20 inch, 1/7 twist barrel. Both rounds are less effective out of a 14.5 inch barrel, 1/7 twist. Quite interesting. Its almost like 5.56 NATO is a velocity dependent cartridge in order to gain maximum potential effect on target.
Shooting 62gr ss109 out of my bushmaster m17s 21.5” 1:9 vs fostech faxon barrel 16” 1:8, melons explode considerably more when hit from the bushmaster.
The 55 grain bullet out of a 1/12 20” barrel was impressive. Palmetto now needs to add this to their kits (although it’ll never be in stock, like most everything else).
@@rodiculous9464 Yeah, you're "limiting" yourself to THE most effective load, at least at closer ranges. I'm always dubious when someone makes radical changes away from the original loading for any cartridge. Radical load changes are usually the result of attempts to make the cartridge into something it was never intended to be. The 5.56 was never intended to be an 800-yard cartridge. It was designed for close assault, which rarely entails ranges of longer than 300 yards. The M193 load out of a 20-inch, 1:12 barrel is simply devastating.
@@careylymanjones why would a 1:12 twist be more effective than a 1:7 twist in the same barrel length for a 55 grain? More energy going into velocity rather than spin? Or less stable bullet so it tumbles sooner?
@@SR-wz2iv someone correct me if I'm wrong, but to my understanding, it does create more velocity and just enough spin to stabilize until it hits something. Then it tumbles and wreaks havoc. But The rule of thumb is The heavier the bullet, the more twist you need to stabilize it.
@@SR-wz2iv Less stable bullet. M193 in 1:12 barrels was famous for devastating wounds in CQB. You gave up some long-range accuracy, but the M-16 was designed to be a 0-300yd rifle that could reach out to 400-500yds in expert hands. Fast-twist barrels and heavy bullets are an attempt to make it a 600-700yd rifle. This is arguably useful in the hills of Afghanistan, but most of us aren't in Afghanistan. Making 100yd shots in legitimate self-defense is pretty rare. I don't think I've ever heard of anyone ever needing a 300yd shot in self-defense. Giving up the devastating effect of the light bullet/slow twist barrel combination for the dubious benefit (for civilians) of extended range seems unwise, to me. My rule of thumb is that the original bullet weight in any given cartridge is probably best for the original purpose the cartridge was designed for. And if your needs change, you may be better off looking at another cartridge, rather than screwing up a good cartridge by trying to make it into something it wasn't designed to be.
@@careylymanjonesWhile everything you’re saying is correct I’d take a 77 grain bullet over a 55 grain bullet for self defense it’ll have a considerable advantage in muzzle energy even say a 16 inch barrel 1/7 twist with a 77 grain OTM would be absolute devastation obviously even worse with a 20 inch barrel
I'd like to see a Part II comparing the results of a 10.5" modern pistol with different bullet weights, especially some of the newer, heavier stuff like the 77 gr bullets.
Thank you, and anyone one helping you, for this presentation. I especially thank you for the respect shown to Paul Harrell and his crew. Both channels give outstanding quality and entertainment. BTW, this 4 tours 11B can attest to your results. The 20" barrel is better for either round regardless of twist rate.
I have been waiting for this test! Josh and Henry are planning to compare the 1:9" twist to the 1:7" twist in 16" and 20" tubes with M193 but haven't got to it yet.
@@petesheppard1709 9 Hole Reviews has brought up the issue of the faster twist "over stabilizing" the lighter pills. I have inquired and they say they are going to compare 16" and 20" barrels with 1:9" twists to 1:7" twist rate tubes with different weight bullets
@@dbmail545 Thanks! I'm looking forward to it. Sometimes there seems to be duplications by different channels, but the varied results are very interesting to consider. What would be really interesting would be a comparison between 1:14 and 1:7; where they started and where we are today.
Fun fact: M 16 was first adapted by USAF to replace M1 and M2 carbines for USAF base security. I think it was General Lemay who got the M16 in the door
Update, military went to short barrel for easy movement in rooms. In my day, m16a2 was used. Room clearing was done point shooting. Not shouldering the weapon, or scope aiming. No problem hitting center mass target. Less time. Easy to swing on next target without having to move your head. Just trained in old school. Love to find a cilivan m16a2, love the sights.
I have ARs in SBR, 16”, and 20” lengths. The SBRs and carbines are my day to day truck guns, for the simple reason that I’m old and fat, and they weigh less and are handy. But if I had to go to war, my 20” A4 is the one I’d want to go to war with.......iron sights, bone simple, reliable, accurate, and still not too heavy. I love a 20” AR.
I hear ya, got several lengths myself. My 20" AR has a SS match grade barrel, 1/7.5" twist with a 1-6x, shoots 77 grain with excellent results. I'd like to get an A4 at some point, for the same reasons. Got some Speer 75 grain gold dot soft points for my shorter AR's. The 14.5"(pin&weld) with irons is so simple and light, got a LMT rear sight.
I'm getting old(er) and fat(ter) too, I am an advocate for learning to use irons sights but I am becoming a fan of modern choices in optics. with the iron sight option of course.
recondo886 Yeah, that’s the same reason why I have some sort of optic on all of my other ARs, as well as on every other kind of rifle I own. I just like keeping my A4 as simple as it can be, with the carry handle sight and everything. I used to have a 4x32 RCO ACOG on it, but the short eye-relief didn’t work that well for me with the fixed length A2 buttstock. So that’s why I converted it back to the iron sights. They just work, even if my 68 yr old eyes can’t see as far as the sights will shoot. I ended up putting the ACOG on one of my carbines. But even then, it seems like the primary advantage of the ACOG these days for me is the relatively light weight. I find a 1-6x LVPO to be a lot more easy on my eyes.
This is interesting, Mac, especially the last one with the meat targets. Unfortunately, it's been done before (hell, I've done it myself but without a hi-speed camera) so I was pretty sure what the results woukd be. Remembering back to the dust-up in the late 60's - early 70's (and trust me, I remember it well, although I was never in the military) the main complaints I heard or saw in print were regarding the ammo's ineffectiveness were a bit farther down range than 25 yards. From what I was able to gather, it seemed the major complaint was at something beyond the 125 yard/meter range, after the bullet had "gone to sleep" - we all know that rifle bullets settle or stabilize at around that mark. I have confirmed this on some of those big mature southwest jack rabbits... hit up close, under 100 yards, and those 55 gr. FMJ's blow the snot out of them. Hit them farther out, beyond that 100 - 125 yard range and the bullet simply pokes a hole. Granted, even a big jackrabbit isn't large enough to really test a bullet, since they are only 10 - 12 pounds and relatively thin skinned & bodied, but the .308 ball ammo out of an HK or FAL was much more devastating out to 250 yds. or so. Shots beyond that were a bit difficult on such small and usually rapidly moving targets... not that we didn't try, of course. I did blow one up pretty good at a stepped off 400 yards but it turned out the bullet hit under the hapless bunny and sent gravel shrapnel into his soft belly, opening him up in a most spectacular way. Ok, so it's time to put the the legendary accuracy of the AR platform to the real test! Set those melons up at 150 and 200 yards and repeat the tests! We've seen you paste those steel targets over and over again with the AR's (even AK's!) at that range so we know it can be done, even if you have to scope the rifles to get a more precise shot on target. That will be a much more valid test than shooting at 25 yards. Personally, I've always considered the AR platform (1:12, 55gr) as a 150 yard gun, unless using my 20"/1:7, stainless, bull barreled, 10 pound upper... then it goes out to maybe 300 yards with the right ammo. It's super accurate but I damn sure wouldn't want to lug the thing around with bullets coming back at me! Thanks for all the work you put into the vids, I well aware of how much effort goes into making these video's... just so we can all sit back and Monday morning quarterback! Cheers, jc
Re: "Personally, I've always considered the AR platform (1:12, 55gr) as a 150 yard gun, unless using my 20"/1:7, stainless, bull barreled, 10 pound upper... then it goes out to maybe 300 yards with the right ammo. It's super accurate but I damn sure wouldn't want to lug the thing around with bullets coming back at me!" Your observation tracks with the design parameters of the weapon, and its intended use. The whole point of assault rifles, as a class of military small arms, is that they fire an intermediate cartridge, one whose size, range, power and weight fall between those of a full-sized rifle on one hand, and a pistol or SMG on the other. During the Second World War, it was noticed by several militaries around the same time (Germany, USSR, U.S.) that there existed a need for a weapon which was intermediate in power/range between pistols and SMGs on the low end, and full-sized rifles and medium machine guns on the higher end. It had also been seen in action that most wartime infantry small-arms use occurred inside 300 yards/meters (as the case may be). That range envelope of about 300 yards is precisely the one in which an assault rifle like the M-16 was designed to function optimally. Stoner's team designed M193 55-grain FMJ/Ball to fragment at sufficiently high muzzle velocities, from roughly 2700-2800 fps and up. Using that figure as a benchmark, the 20-inch barreled M16 was optimally effective inside 150-200 meters, and the shorter barreled carbines somewhat less so. The Army and Army Ordnance went back and forth, and the former eventually requested that the weapon be "effective" out to 800m (fixed carry handle sights) or 600m (removable carry handle sights). "Effective" in quotes since the ideal range envelope was well inside of that using M193 or the later M855 ammunition. In plain language, the slug was still potentially lethal out to the limit of the sights, but less-so than at ranges inside 200-300m, or typical combat ranges. The trade-offs arrived at by Stoner et al. were part of what it took to make a weapon compact and light-enough to qualify for Army requirements for the light rifle program - which stipulated a select-fire weapon using .224-caliber ammunition. But Big Green wanted it both ways, which is why the program had elements of both assault rifles & intermediate cartridges in them, along with holdover ideas such as being able to engage targets at more-traditional rifleman type ranges out to 600 or 800m. Later advances in ammunition design dramatically improved the performance of the legacy AR15/M16 system, including not just use at close/medium range, but out to 800 yards or more. Mostly, these improvements dealt with using a heavier slug and a faster rate of barrel twist to stabilize such long and relatively heavy projectiles. Today service rifle competitors routinely use 80- or even 90-grain bullets for 1,000 yard matches, and tactical personnel often use 75-77-grain projectiles even at more moderate ranges.
In the early 60’s my dad worked as a gunsmith. Some guys in the shop started to talk about a new rifle and ammunition going to be used in vietnam. They showed some pictures of the bullet effects. One picture was of a dead guerrilla with a little hole in it’s chest and one when it was rolled over. It’s heart fell out of the hole in it’s back.
@@donski1519 1/12 wont stabilize it. Paul Harrel has a video up showing it won't even stabilize green tip. ua-cam.com/video/bKQizbg1zBw/v-deo.html&ab_channel=PaulHarrell
Very interesting indeed. I may swap to the longer barrel now after watching that. So, can we see a similar test with 300blk barrel lengths and different twists? Please... when you can of course. 😆
You don’t get as much of a velocity improvement with .300blk as you do with 5.56. Mrgunsngear has a video on .300blk velocities with different barrel lengths
Yeah I'd like to see the 300 out of the 9 and 20 inch barrels with the 1n12 and 1n7 twist because you hear all the time the 9 inch performance is better.
@@echofoxtrotwhiskey1595 Correct, but I do believe the Hornady SBR 5.56 has faster burning powder to make the performance a little better, but by how much I don't know and honestly for the price, not as cost effective as just having a longer barrel to begin with.
@lilbeserk Yeah and the US was fighting off human waves in Korea, guerrillas who couldn't expect medvac or get taken to a proper hospital in Southeast Asia and if push came to shove, a Soviet Union that would not have the money to send helicopters to save every screaming Ivan. If the morale was reduced from screaming, they'd probably just put a bullet in them themselves. And if they did live, they'd come back a few months later to kill you. 5.56 was chosen because the US expected to fight Soviet steel beasts and thus every man would need to be carrying a LAW on his back. Lighter ammo would be needed for those conditions. And when special forces used 5.56 in Vietnam after they ordered AR15s, they did note it was _VERY_ deadly. Let's just say, the M16 was pressed into service because it didn't leave people screaming.
Exactly. since Vietnam special operations units have had their choice of weapons, guys were literally fist fighting over car-15's and stoner63's and would trade a nice watch for a half arsed cobbled up 30rd mag, not many guys chose m-14s and m 60's 🤔, occasionally somebody preferred an AK, but once again not a full power cartridge "battle rifle". in my reading/listening most special operations vets rave about the m-16 being great, not a "underpowered jamming plastic death sentence"
@NOThotsquidjunk There are people in the replies to this very comment agreeing with your clearly sarcastic repetition of a commonly repeated, but patently false, assertion. The requirements for 5.56 that the military was looking for, as outlined in their trial reqs, was a.) .22 caliber catridge b.) much lighter weight so more could be carried c.) was softer shooting so it was capable of controlled full auto fire comparable **D.) equal/better wounding to/than the 7.62 NATO at the distances considered relevant for modern combat (doctrine shifted to 300 yards and nearer)** I.E they ordered up a cartridge with equal-ish lethality to the .308 that was smaller. When they finally accepted the 5.56, it was reported internally to have EQUAL OR BETTER TERMINAL PERFORMANCE/WOUNDING CAPABILITY to current 7.62 NATO rounds. So not only was it ordered as specced to comparable lethality, it was adopted using data that showed it was just about as (or even moreso) lethal than what they currently had. Allow me to repeat: They put out a request for a .22 projectile with the requirement of comparable terminal performance (within 300 yards at least) to .308. They were given data and reports that suggested this new round was actually more lethal than the .308 in many circumstances. And they adopted it. Regardless of the truths of .223/5.56 vs 7.62 NATO/.308 and their terminal effectiveness, those are what they thought they were gonna get, and once they got data saying it did that, they adopted it. If you accept the premise that .308 is not designed to wound, then you cannot argue the 5.56, BELIEVED (true or not) to be its EQUAL by those who adopted it, was designed to wound.
Back in the late 1960's the M16 with the one and twelve twist - twenty inch barrels shooting the fifty five grain M193 bullets were very devastating on soft targets in Vietnam. These bullets were known to start spinning when it hit the soft targets, spinning and yawning, then exiting in different directions. Causing massive wound damage ! A very devastating bullet for combat !
The early AR-15s with the 1 in 14 twist developed quite a reputation in Vietnam. Unfortunately testing showed that it wouldn't stabilize bullets in sub-zero weather so they had to go with 1 in 12, lessening the wounding effect.
I do believe they are having a resurgence tho. Quite funny to me seeing people with their Uber short 8" ARs. I know compactness is nice but your losing Ssooo much for it. Hence why I'll always be a 20" man.
@@Patriotusa44 I believe an 8" barrel produces almost exactly half the energy of a 20". It's closer to a PCC than a rifle at that point. May as well be an entirely different caliber compared to what 5.56 is capable of.
Loved the shout-out for Paul Harrel, would love to see a collaboration of both channels. Well, I'd love to see a collaboration between MAC, Paul Harrel, Iraqveteran8888, Brandon Herrera and Garand Thumb, but last time I checked something that entertaining and informative was one of the signs of the apocalypse.
It was absolutely the best for jungles. The tighter twist, better coefficient and heavier bullet were developed to reach farther. It was needed for the more open terrains of the last 30 + years.
i know that ar site, and those people are idiots. there is something else 55 grn fmj does at close range.....holes 1/4 inch ar500.....which m855 has a hard time doing do to lack of velocity.
First introduced to the AR-15 weapon system was thru magazines back in the late 50's. Did not see any in the gun stores until I came back from Vietnam in 68. Joined the USAF in Feb of 64 and went to Turkey. Our commander had any troop being sent to Vietnam go to the Armory and get familiarized with the weapons that the AF had available for us at the time. That included everything from the .38 revolver up to Ma Duce. Got trained on how to handle, use and shoot the M-16 and especially how to insure it was cleaned after usage. They were reports of problems with the weapons system filtering back to us at the time. The Gun Smith told us that when we went thru the US on our way to Nam, we needed to pick up a cleaning kit for a .22 rifle and he showed us the bore brush we needed also. I bought 5 of them to take with me. Glad I did as cleaning kits were nonexistent when I got there in early 66. Had some friends, in the USMC, that were stationed across the street from us at Danang who I bumped into. I gave them 3 of my cleaning kits with the bore brush. shortly afterwards they were issued cleaning kits to help maintain their weapons. Massive difference in reliability of the weapon system. Many loved the weapon but many hated them and said in the heat of battle sometimes they would grab a AK to use as it held up under any conditions they encountered. As I was not a combat troop, I cannot not deny what they said and merely repeating what I was told at the time. All we did was go to the range and get to shoot the weapons that were assigned to our Unit and then bring them back to clean and return them to the NCOIC of the Security Policed det assigned to us. Currently I own a Ruger AR-556 with a 16.5 inch barrel and am looking at locating a upper with a 20 inch barrel. I like th ballistics I've see with it better.
Great video. Many years ago as I entered rifle ammunition reloading, I started working up handload recipes for .223 Remington and 5.56x45 mm cartridges. In my research of the projectiles, I discovered that the M193 full metal jacket boat tail bullet with cannelure must accelerate to a minimum muzzle velocity to provide optimum performance. The M193 when fired at it's designed muzzle velocity is designed to tumble after a short penetration. The centrifugal force produced by the tumble effect should break the bullet into several smaller pieces at the cannelure enhancing the hydrostatic shock within the target. The M4 rifle with the shorter 14.5 inch barrel may have difficulty extracting the full potential of the M193, M855, or SS109 projectiles. Having said that, the M4 is still a terrific, reliable and accurate firearm.
I would also like to see a test of the meat target done with the 14” pinned barrel for comparison because 14” - 16” barrels are more common today than 20” barrels. We thank you for all the testing though, as do the ants and other insects.
Although not scientific testing, still the question begs to be asked; which would you rather be shot with? And the answer is: not a damn one of them!!! I still cease to be amazed by Stoner's brilliance.
Nice shout out to Paul Harrell, This just confirms what I knew in the Marines and why I still to this day love my A4 over the M4 they offered me when I was in.
This goes back to what we have known for a very long time. Push a round as fast as you can and give it just enough twist to stabilize it. If you have to compromise on one side it is better to "over stabilize" than under stabilize as accuracy is what's most important. Do the same test but for accuracy instead of terminal ballastics and it will confirm this. Also that KS for giving a shout out to PH. Your a stand up guy.🙂
Maybe the right choice in 1959 since practical, affordable body. armor for front-line troops didn't exist, but today personal body armor that can stop m193 is more or less universal.
Being in the Marines in the early '70s I was very familiar with the a1 with 1-12 twist, 20 in barrel, m193 cartridge. A good combo out to 300 yds give or take. My understanding is the m855 and reduced barrel twist added another 200 yards or so to the rifles accuracy.
I'm surprised the M193 did worse on the melons than the M855 with the 1/7 twist barrels, I guess it didn't destabilize as fast as the M855 but in a real life meat target the difference would likely be negligible.
Thank you for doing this comparison. Been thinking about a 20" build for 55gr since it's the cheapest and most common (usually) and have been trying to figure out if the slower twist rate has better terminal performance. Nobody wants to talk about anything except "1:7 sbr's". Info like this is hard to find. Thanks again
Buy the parts, make one! Building a regular flat top AR is one thing, but building a stripped fixed carry handle upper, omg so much more fun and lasts longer than a half hour.
The results of this is awesome. I absolutely love my A3 style m16. I absolutely love the fact that this kind of proves what I have heard some combat vet say which is the longer barreled AR-15 / M16 are actually much better. I just wish you could get your hands on m855 better right now. With all this ammo shortage and craziness going on finding ammo's getting hard.
1 year later, if you have Academy Outdoors near your area, they have pllllleeeennnnntttty of M855 Green Tips on their shelves to the point it’s basically the only 5.56 they have! I got their 200 rds range pack here for my Daniel Defense MK12…..I know it likes 77 grain match grade rounds the best but damn it! At $35 for 20 rds, it’s too expensive so the 62grain green tips will do. I do know not a lot of indoor ranges will allow you to shoot the green tips because it’s steel core makes it a semi-armor piercer but the one near me do allow it so I go there a lot so yeah, it’s out there if you know where to look.
I think it is “Hydro-dynamic” shock. Some have said that it is Hydraulic shock. Hydro-static refers of a pressure that is essentially “static,” or constant. FWIW
Hydro-dynamic shock is when water abruptly slows down, like the water-hammer effect in your house pipes. Hydro-static shock is energy being dumped into static water, forcing the pressure wave to propogate through it catastophically.
I fell and landed on my side from 30 feet. my lungs were fully intact A watermelon falling from 30ft would leave a big splat. Just throwing some perspective out there for the tissue physicists. How much velocity is lost on that bullet after it goes through the clothes and rib cage? I imagine the hydrostatic shock on lung tissue is pretty minimal past 250-300yds.
Yeah well so would an equally well placed .22 LR. at only 25 yards. What happens at 300 yards? The difference could be a clean pass through verses a devastating wound.
Yup. Another important fact is what the bullet has to penetrate before hitting flesh. In Vietnam many enemy troops had on a shirt or smock. Fast forward to today and many are wearing load vest and mag pouches and other gear. That is why in gel an important but often overlooked metric is the neck length. A long neck that expands violently is going to be better at gear penetration where a short neck and consistent expansion is going to be a better hunting round. Because animals don’t wear coats and mag pouches. But hunting would be more fun if they did.
@@ryanpm4460 Don't forget also that one of the main complaints about the efficacy of the A1/556 in vietnam was how it struggled with brush. Of course it's devastating if it tumbles the second it touches a person, but it's not so devastating if it spins off into nowhere after clipping a big leaf
If you pattern that on a piece of paper, most people don't realize with that slow rate of twist that bullet is coming out of the barrel and turning sideways to keyhole. That's why it destroys the watermelon. That rate of twist does not stabilize the projectile and it hits sideways.
First video of yours I’ve watched. Loved it. I’d like to see a comparison damage of the SP1/M855 ball to the 77 grain bullet from a 16 inch barrel with a 1/7 or 1/8 twist. Thanks for your effort here.
Hey Tim are you still planning to compare the BCM MKII upper to your MK12 in terms of accuracy/rigidity? I just got a BCM MKII and I'm interested to know if they truly are more rigid. You're the best!
The thing about this test is that both of these rounds are known to have pretty wide variations in yaw depth, and that's the key factor in what you are wanting from these
The twenty inch A1 was also very easy to shoot. It is also lighter then it looks. For an Infantry men in Korea the twenty inch with an optic would be ideal.
The xm193 ball was designed to perform with a 20" barrel with the right barrel twist. Thats why guys had issues in Vietnam when they decided to chop the barrels with the CAR-15. The Russians were a little smarter with the 5.45 x 39mm because instead of focusing on barrel twist and length to get the bullet to perform right. The Russians just hollowed a small space in the top of the 5.45x39mm so no matter what barrel length or velocity they are shooting at the bullet will perform every time and get that tumbling "Yaw" effect . Luckily however we now have the M855a1 it penetrates more then the green tip and fragments like the XM193 like at optimal performance even if you shoot it out of a shorter barrel.
I don't think the choice of targets was accidental. If I remember correctly, a watermelon was shot at an "informal" bbq by the prototype rifle and that convinced a general with the U S Air Force to give the rifle a chance in military service.
USAF Chief of Staff Curtis LeMay wanted the new AR15 so badly that he nearly antagonized President Kennedy and Secretary of Defense McNamara into firing him, he badgered them so much for the funding to buy them. The USAF didn't adopt the then-new M-14 service rifle, as LeMay felt it was unsuited to the mission of his air police and base security personnel. However, when an AR15 was demonstrated to him at the now-famous picnic and he had a chance to fire the weapon, he was sold and thereafter worked very hard to get them for his service. LeMay's requests were turned down initially, but after U.S. Army Special Forces advisors had used the weapons successfully in SE Asia in the early 1960s, Kennedy and McNamara eventually relented and allocated the money and the Air Force got their rifles.
@@GeorgiaBoy1961 Too bad they decided to switch powders and make changes that caused reliability problems. The government just can't help but mess up a good thing.
I know everyone calls it "hydrostatic shock". I don't have a degree in engineering, but I remember my physics class. The bullet is moving! Statics is the study of non-moving forces working against non-moving items. If anything, the shock is hydrodynamic! Yes, I'm right, look into it, go ahead and argue with me on this!
I do have an engineering degree so let me clear this up for you. You’re correct that the study of statics vs. dynamics is physics of forces in stationary vs. moving bodies, but this experiment is hydrostatic forces which is a different study. Hydrostatic Pressure is relating to or denoting the equilibrium of liquids and the pressure exerted by liquid at rest respectively. Hydrostatic shock is a controversial topic usually in reference to hydrostatic pressure from a bullet impact and the results due to the pressure wave. So hydrostatic shock is the correct term here.
I took stills of each barrel combination w/ bullet weight as 1) striking watermelon target 2) at "max explosiveness point [?]) on target; then created a layout of the stills to allow comparison of each demo. Damn, what a "jarring" visual reference to allow someone to look at the effect of what their particular barrel/bullet weight combination has on terminal performance. Thank You for this presentation, Mac!!
Just go to Portland or Seattle I hear they have lots of "Commies" so you could take their shirts and you would even be helping their mommy's get them out of her basement. I hope you like the color black because that's all they seem to wear.
My recommendation is to use gallon milk jugs full of water, but you could try to make jello in a few and shoot them. The milk jug doesn't explode like the watermelon, but gives you a good simulation of what a bullet will do. I used to have a CUR-2 in 5.45x39mm. The milk hug showed the projectile going out sideways once I pieced the split back together.
The reports of crazy aggressive wounding were actually with the earliest 14 twist barrels used before the Ordnance Corps got their mitts on the AR and added the fwd assist and screwed up the ammo. Rumor has it that the 14tw barrels were produced on worn tooling that produced actual twist values even slower-- perhaps even 16 twist in some cases. Green Mountain makes a 14tw A1 barrel I'd love to try.
what I take from this is, in a firefight dont ever hide behind a watermelon , them things are bullet magnets.......
firefight raging, both sides furiously fighting.. in walk a lonely scared water melon.. both sides cease fire look to one another then to the melon.. (will Defoe shouts boondock THERE WAS A FIREFIGHT) both sides proceed to shoot the melon to shreds and call it a day
Copy that! Neither watermelons nor packages of ham are cover.
I carry a Smith and Wesson 500! 😁 There is no cover, only concealment! 😈
@@Hoof8989 Love that scene. ua-cam.com/video/MsuH1msEkvM/v-deo.html
Salt of the Earth wisdom! 😂
And today we are testing 6 bullets on 6 watermelons, as the 6 watermelons are cheaper and easier to find than 6 rounds of 5.56 ammo...
Lmao
bulk ammo at 5 am
Sadly true
@lilbeserk preaching to the choir brother. I just hate the gouging that's going on and sadly from places I'd never expect to do it.
Today, we are shooting watermelons at our 5.56 round mounted on the table..... hopefully, we do not drop one of the 5.56 rounds...
Appreciate the shout out for Paul Harrell, Tim! He is truly a national treasure.
3:33 *M193* through a SP1, 20'', 1:12 twist
6:14 *M193* through an A2, 20'', 1:7 twist
8:32 *M855* through the A2
10:38 *M855* through a M4, 14.5'', 1:7 twist
12:42 *M193* through the M4
All above used watermelons
15:28 *M193* through the SP1, meat target
Thanks
While at the rifle range in Fort Dix, 1973…A Drill Sergeant told our platoon that if you made a shot with our 20” 1/12” M-16 (55 grain ball) and hit the enemy in the back of the head, his face would come off like a Halloween Mask. I never forgot that.
Immediately thought of the scene from the office where Dwight wears the cpr dummy's face.
So a Design Engineer for an aircraft company in the late 1950s/early 1960s with a slide rule got it right all along.
Yes He Did!
Pretty much.
No, Eugene Stoner was the principal designer of the AR but there were other entities involved with the development of the 5.56mm cartridge and the twist rate in the barrel, Stoner didn't design it all himself down to the last little detail.
And this test isn't exactly the best way to evaluate the bullet's affect on the human body, the watermelon and human lungs may have similar amounts of water in them but the watermelon is solid and lungs are full of air, also different organs have different densities and even then you've got solid bone coming into play, ballistic gelatin isn't a very good representation either but it's cheap and provides a repeatable testing parameter so that's why it's used so much in the industry.
Furthermore the results might have been exactly the same had they switched watermelons, you'd really have to shoot batches of them and get the average of each one for any kind of serious comparison.
Videos like this are good for entertainment but they're not really proof of anything, he pretty much says that at several points in the video.
He also used an astrolabe and an abacus to aid his design.
@@f3uibeghardt522 legend tells of his use of sextant, and perhaps dowsing rods, as well!
Although not scientific, it was enough in 1960 to make a General Curtis LeMay order the AR15 on the spot for USAF use!
Hey since we are talking about these details, just in case anyone is as fascinated as I am with the evolution of this rifle/platform, @SmallArmsSolutions has a great deal of knowledge and history on it in his videos. I definitely learned a lot from him! Thanks!
Hasid lafre No I’m pretty sure it was either a 1:14 or 1:12 with M193
@Mr. Spetznaz hey just don't worry about our m16 commy...lol 😆 kidding...not sure what you are asking about so I might have to look into it myself!
Hasid lafre M193 from the 60s is not that different than it is today.
@@echofoxtrotwhiskey1595 different weight, different powder, different construction. Only thing the same is the caliber
In the greatest tradition..... gunny would be proud.... RIP R Lee Ermine
I can still hear his Oooo RAHHHHHHH!
'Ermey'
He loved blastn watermelons. Miss you ermey
My Conclusion:
Getting hit with any combination of these bullets and barrels will ruin your life.
Unless you're a watermellon, in which case it is basically your calling.
Exactly
Look at Gaige Grosskreutz arm. Live test.
"Top Gear Top Tip, don't get shot."
@@E_Legal_Alien I've wondered about that as well. That was 223 fuji at very close quarters. I think it was 7ft roughly if I'm not mistaken. So non hollowpoint at close range still did that to his arm. And ppl say 223/556 isn't enough? Can someone explain that to me please
The first time I ever saw an AR-15, I was about ten years old (54 years ago), when I was watching my neighbor shoot his into a creek bank from about 100 yards away. He was shooting uphill from the targets which were mostly tin cans. One I remember in particular was a can that the bullet hit directly on the lip of the can, which was apparently laying on its side. You could see where the bullet impacted the thick metal ring at the top of the can, and literally opened the side of the can like it might have done to one that was unopened or maybe one that was filled with water. I knew at that moment that this was one bad ass rifle!
Amen
You were missing the high tech fleece bullet stop and that obviously invalidates any findings!
New and improved high tech fleece bullet stop. Gotta make sure we use the latest and greatest.
And the leather couch skin
Don’t forget the pork chop pectorals.
What.....no one mentions pork ribs in front and back ?
Can't forget oranges for lungs
Paul Harrell would approve Tim
“I never saw anybody shot with the rifle I’d wanna trade places with” Clint Smith
“It dicks em up” also Clint Smith
The guy's arm in the news tells us the 5.56 is not a round to criticize, it's a specal kind of hell flower that blooms with devastating effects.
You mean Gaige Grosskreutz AKA Bye-Cep.
I remember watching his arm turning into a puff of red spray on live stream..He got the Kyle Rittenhouse treatment. The other guy laid down and went to sleep instantly.
5.56 effectiveness is only debatable outside of 400 yards. inside 100 a 64-124gr bullet that leaves a muzzle at 2,600-3,000 fps will put you down easily. Barring any freak circumstances (Miami shootout).
@@joebenson528 124gr in a 5.56 coming out at 2600-3000...wtf are you talking about
@@BryceKimball7.3 maybe he’s including all intermediate cartridges in that?
And suddenly, barrels with 1 : 12" twist are back in style. 😉
Yes I saw the point of hit kept going lower and lower as he changed rifles to make less damage to the watermelon.
The original 1 : 14 is where it's at. ;)
@@TwinklesTheChinchilla that what I have and with62 grain I key hole at 15yards
@@thebushbunker What do you have? 1-in-14s were designed for 55grs, and 1-in-12s for 55gr tracers. A 1-in-9 should be sufficient for 62s, even if most of those are longer than normal due to the lighter penetrator of the M855.
@@TwinklesTheChinchilla I have a 1-14
My Conclusion:Scientific- Don't get shot with a 5.56 mm!
I prefer 20" barrels and I have two, but I have 2 16" barrel C.A.R.'s
Final conclusion. DONT GET SHOT..
... with a 5.56 round.
@@jakleist anything 22lr from close range is enough to bleed you to dead
It's not the picnic Hollywood makes it out to be! 😂
Its how I defend using a 10.3....lol
Exactly, any one of those would kill you.
When I was in boot camp in 1971 we had the slab sided M-16's ( No forward assist) with the skinny barrels and three prong flash hide . Infantry AIT we had the forward assist rifles with a bird cage flash hider. Late I went back to Ft. Polk as a range officer for BCT and infantry AIT. We had time on our hands so some of us shot a lot and I found the the 55gr ball ammo sometimes didn't penetrate both sides of a 55 gallon drum. The bullet broke up on the other side of the barrel you would see some exit holes that looked like it was hit with bird shot. Same with ammo cans filled with water and sometimes there was no damage at all to the exit side of the ammo can. We used to shoot water filled ammo cans to show boots what the M-16 did on impact and I wish I had some of those un-shot cans now.
I just got done reading something that said the 55gr. tended to fragment on impact, which is what they wanted, but it was impossible to predict where the fragmentation would occur because it wasn't consistent. So, they moved to the heavier bullet to get away from the fragmentation concept.
@lisar3006 - Back in the 1950s, when Eugene Stoner and his team were working on the light automatic rifle project, the army specified that the weapon be chambered in .22-caliber, so they had to meet the lethality requirements in another manner than by using the traditional answer of increasing bullet mass. The wounding capability was to be equivalent to or better than the .30-cal. Carbine 110-gr. round. Stoner's solution was to pump up muzzle velocity, and also to take advantage of the inherent yaw of light-weight projectiles at high velocities.
This was done by making the M193 FMJ/Ball round with a crimping groove or cannelure. At impact velocities at or above around 2600 fps, the slug would shatter into several pieces, each of which generated its own wound channel or track, thereby mimicking the performance of a HP or expanding bullet without actually being one. This is when encountering a soft target; when hitting something more substantial, the bullet breaks up even easier - as you saw.
The M855/SS109 62-grain projectile was designed by NATO. In order to enhance its effectiveness against barriers, it was given a steel cup or core inside its lead matrix to add weight and momentum down-range such that it would penetrate a standard Warsaw Pact metal helmet at 500m. Not truly armor-piercing, this round was termed "enhanced penetration" instead. The improved penetrative ability came at something of a cost, however, in that the new 62-grain load did not always fragment reliably in the terminal phase of flight, as the older 55-grain load was designed to do.
Given the dependence of the 5.56x45mm NATO round - whether in 55-grain or 62-grain - upon high MV for optimal performance, it should come as no surprise that inconsistencies began to be encountered as barrel lengths were shortened during the 1990s. These shortcomings led to the development of new loads which performed better at lower velocities and also against barriers.
The considerable velocity loss between the 14.5" barrel vs the 20" barrel was clear in the lack of damage to the watermelon.
Yep, 556 was designed for 20 inch barrels. Once you shorten the length, you get rid of the yaw in the wound channel.
@@jayklink851 No that's just M193. You sound like a bitter oldhead lol
Something to consider is that not all M193 is the same. IMI M193 goes well over 3000 fps out of a 16" barrel and is around 100 fps faster than other brands at 16". Some chrono results indicate the difference in velocity is negligible out of the shorter barrels (10.5" and under). As long as the round is above 2200-2300fps when it hits the target, it'll do 5.56 things. Longer barrels at range really are comparable to shorter barrels at close quarters.
@@keres993 Yes, but "5.56 things" is very vague. 5.56 may impart hydrostatic shock above 2200fps, but the difference in damage done at that velocity vs something like 3250fps (20" velocity) is very dramatic. In this video we can see what a 300ish fps difference makes when it comes to terminal effects, so it's obvious that barrels under 14.5 would be even more underwhelming.
@Lost_Achaean True, but those same modern loads produce even more extremely damaging wound channels out of 20" barrels. There is no replacement for velocity.
My Dad had friends in the Agency in the very early days of Vietnam 61-62 and the then AR-15 already had a reputation of massive damage, and that was with the 1-14 twist. It would be interesting to see a 1-14 vs 1-12 comparison. Great video, thanks!
Something tells me Gunny is smiling down from heaven right now.
May he Rest In Peace
🦅🌎⚓ 👹🐕🇺🇲🎯⚔
Future generations will be doomed having no gunny to educate them on reality.
@@Yugetubes Gunnys gone and not breaking his boot off in youguns asses anymore and look where we're at... kids that dont know if they're a boy or girl are rallying support for commies and burning cities. Pitiful lol
My dad served in the Corps back in the early 80s and was issued an A1. Growing up he told us stories of how you could shoot a man in the chest and the round would exit through the guys leg. Never had the same experience during my time in but this test lends some creedence to what he told us.
Lotsa documented cases of those types of wounds in Nam ...
@@taproom113 well I'm pretty sure that's where the stories came from mostly. Especially considering that after they switched to 1/7 and m855 the stabilization was significantly different and more effective compared to 193 and 1/12
@@devildog1989 Exactly. Thanx to you and your Dad for your service! Semper Fi & welcome home ...
@@taproom113 dude, all I can say is thank you, i appreciate it and I'm sure that my father will as well.
My brother is a physician with many years of trauma care experience, and he related to me years ago that bullets tend to ricochet around quite a lot inside the body, if they don't pass cleanly through, and encounter bone. Sometimes, if the slug is tough-enough and possesses sufficient kinetic energy, it passes through bone, but often times it fractures it and/or bounces off. That's how someone shot in the upper body can have an exit wound a long ways away, even well down an extremity. I don't remember how the subject came up; we don't habitually sit around talking about such gruesome stuff.... maybe it had been a tough stretch in the hospital treating a lot of GSWs after a gang war or something like that, and he needed to blow off some steam or something.
Introducing the “fat man” meat target: two hams, a watermelon, held together with gorilla tape 👍🏼🇺🇸
I call it the "politician" with his head stuck up his own a**
And don't forget the new and improved fleece bullet stop. Perhaps instead of the fleece, we can stop the projectiles with inane run-on sentences filled with anti American sentiment.
@Leslie Dodds Oooof. Fish stories and run on sentences just keep getting bigger.
@Leslie Dodds 70% of us are still not overweight. I'm a 6' 2" and 250 lb vetran. Not overweight. Thankfully having served overseas I know most brits are awesome people. Not elitists blowhards. As for the other bit. Religion should generally be kept out of it. I'm southern Baptist. Here's hoping whatever bugs up you tail finds it's way to a new home.
Good luck passing the gorilla tape 😂
It would be interesting to see this test at 200 yards. The reason I say this is that recently I was reading Hatchers Notebook and they conducted a test where they shot M2 Ball into a wood (oak IIRC) target at close range (maybe 25 yards) and the bullets yawed and had little penetration. Then they shot the same type of targets at 200 yards and had straight line penetration of around16". Their conclusion was that it takes some distance for a bullet to completely stabilize. I found that to be most interesting and wonder if that is common to all bullet diameters.
Nice test, well done, and fun to watch.
Depends on twist rate, barrel condition, bullet length, to some extent barrel length and temperature. Yaw damping takes a bit of distance no matter what. Night fires with M16A1 with tracer was spectacular with different rifles showing slight differences in the yaw damping as seen from the wobble in the trace. Sometimes it would wobble close then far out as they destabilized again. Tracers lit off bright about 15 meters out at a minimum.
"Short-range" instability is actually normal. All of the forces that act on a bullet after it leaves the muzzle take time to "balance".
At short ranges, rifle bullets spiral around the actual / nominal" trajectory. The better the barrel, especially the last couple of inches and MOST especially, the "squareness" of the crown and the better the bullet; the smaller that PRECESSION is.
Exterior ballistics is a weird and wonderful field of study.
Re: "Then they shot the same type of targets at 200 yards and had straight line penetration of around16". Their conclusion was that it takes some distance for a bullet to completely stabilize."
In the vernacular of firearms types, the distance the bullet takes to sort itself out gyroscopically and become stable, is known as "when the bullet 'falls asleep,'" and is thereafter stable in flight for a fairly good distance. That accounts for the difference in the terminal effects of that M2 Ball described in General Hatcher's notes.
The process of gyroscopic instability and stability can be seen in a rapidly-spinning top, which is wobbly and somewhat unstable at the start, but becomes stable and regular in its rotation and orientation within a short interval of a few seconds. It's the same principle, really.
I've seen some videos that explain that there's a velocity threshold that will cause a spitzer bullet yaw in a target vs not. At close range it's going so fast that the yawing is more likely to happen.
It’s almost like the developers of the rifles put a fair amount of research into the weapons platforms they designed. Lots of things I haven’t really put any thought into before. Well done.
I would love to see the difference at longer ranges, 75 & 100 yards. Maybe even with different caliber AR15 rifles. 6.5mm Grendel?
I do love Paul Harrell's videos. He always reminds me of a college professor giving a lecture.
The first demonstration of the AR15 to the Air Force was at a birthday party where they also shot watermelons. FYI that sealed the deal for the rifle.
Never underestimate dumb luck when trying to sell a product 😁
@UCaijndnEsnGJGVgkfJVIKTg I believe it was Curtis Lemay. Dont think the president would be at a BBQ with rifles.
@@zee7056
We *are* talking about the sixties so I wouldn't be so sure tbh 😁 But AFAIK it was a general that was there.
I’m gonna compliment you on having the knowledge to shoot from a sitting position because as Grandmaster Jay says that rifle will knock you on your ass. My buddy and I have our version of the Paul Harrell meat target that we use a Carhartt barn coat for outer covering (New England meat target) and I wasn’t there but he tested a 14.5, 16 and 20” barrel and he said he was surprised at how anemic the 14.5” performed and that the 16” was much closer to the 20” than the 14.5” but the 16 was also a 1/8 twist not 1/7. Thanks for the vid and hope your shoulders ok after absorbing 6 monster 5.56 discharges
Those are some nice bullpups, that kick like HELL!!!
M855 was spect at 1\8, the reason they settled on 1\7 was the tracer m856 round.
I really hope you are being sarcastic about 5.56 recoil. Compared to the 7.62x51 in the M-14 or the 30-06 in the M1 the 5.56 is anemic. 5.56 =3.36 ft lbs 7.62x51 =18 ft lbs 30-06 = 21 ft lbs.
john kendall I’m referring to Grandmaster Jay the leader of NFAC posting that video saying the AR15 is a bull pup rifle with recoil that will knock you on your ass. The 5.56 is a 22 and shoots as such but his video where he was expounding his great knowledge was laughable and that’s what I was referring to. He was also posing with a Clinton ban era AR and claiming he bought it in Germany in 1990.
@@jimbolxvi6428 LOL I knew there was something I was missing. Yea that guy is a real genus. They're a bigger danger to themselves than anyone else.
This has to be one of the most refreshingly entertaining gun videos on your channel! Not saying that your other videos are bad, but this was a very welcome break in your regular postings.
So now the real question is, what would the results be with a 16" ,1:9 inch twist barrel with each type of ammo?
i second this question
As opposed to the 62 grainer which some claim will keyhole from a 1/12, or the 55 grain in the 1/7 which some claim is too fast for 55 grain (yet to find evidence of this 'overstablization' causing problems, but it's safe to say it's certainly not ideal), the 1/9 would put both the 62 grain and the 55 grain in the 'green range' of stabilization according to lots of bullet length/BC/velocity charts. So as far as aerodynamics is concerned, either is quite excellent.
Wouldn't trust the M855 for a defensive role, though. It's too velocity dependent for its primary wounding mechanism and I bet it'd be just a bit too temperamental from a 16" barrel in that respect.
@@angry_zergling keep in mind that m855 shoots well out of faster twist rates because the bullet itself is considerably longer than most other in-class 62gr bullets. I’ve heard people compare their length to that of a more typical 69 grain round
@@Turtletanks Would make since as it's part steel and steel is lighter than lead.
I'm not sure if it'd be that big of an effect, though. I know monolithic copper bullets of a given weight are a big difference (62 TSX and Hornady 75 HPBT are both .942 for example), but I'm not sure if replacing a bit of lead with a bit of steal in such a small bullet would mess with its OAL too much.
EDIT: Just realized I could just, y'know, look up the length of an M855 instead of just give a hunch. Doy. Ahem: M855 is .907. 62 Grain FMJ BT is .813. 69 grain BT is .913. (Note: Made sure I was comparing apples to apples here; since M855 is a FMJ, boat-tail, ball round its compared against the same thing - measurements of hollow points or ballistic tips or OTMs or bullets that aren't boat tailed can be a lot longer or shorter and not good to compare even when they're the same weight and construction.)
So you were right and I was wrong. M855 from IMI at .907 is very close to a 69 grain similarly shaped bullet from Barnes. Hadn't thought it'd be that significant, but it is.
Interesting, 'cause I've heard of some 1:9 twists failing to stabilize 69 grainers but NEVER heard of any failing to stabilize M855. Could have something to do with the type, though - OTM bullets are a lot longer than 'ball' rounds of the same weight and that could explain it.
@@angry_zergling thanks for giving actual numbers, I was only using previous conjecture for the weight comparison but yeah, m855 is a long bullet in comparison to, say, a standard FMJ 5.56 62gr. One issue that m855 encounters though across the board is that because the round isn’t uniform, as in the steel penetrator isn’t 100% uniform with the rest of the round, it tends to have somewhat more open groups regardless of your twist rate, or at least that’s what I’ve discerned from a small amount of research into the subject. Not really a huge deal unless you’re shooting significantly over 2 MOA, which is about as accurate as military spec equipment could reasonably expected to perform (it isn’t your 77gr Sierra match kings, that’s for sure). But people who claim 1:7 is going to “overstabilize” an m855 round usually aren’t aware of the actual construction and length of the bullet itself, and as of yet the only supporting arguments against a faster rate of twist are that
A) the reason the 1:7 twist was adopted was to stabilize the long, heavy tracer rounds that the US military issues and
B) conjecture that a bullet will not fly properly through the air when the ROT is too fast
I mean frankly I don’t know whether people expect precision performance out of a standard military load but even if you wanted to go 300 or more meters with an AR, you are relegated to heavier bullet weights anyways, and thus would probably want a 1:7 twist.
To sum up:
M193 works best in a 20 inch, 1/12 twist barrel (absoluteky devastating), still reasonably effective out of a 1/7 twist barrel of the same length.
M855 is absolutely devastating out of a 20 inch, 1/7 twist barrel.
Both rounds are less effective out of a 14.5 inch barrel, 1/7 twist.
Quite interesting. Its almost like 5.56 NATO is a velocity dependent cartridge in order to gain maximum potential effect on target.
That's why I'd trust a 5.45 AK74 More. That hollow cavity in the bullet guarantees yaw even in short Krinkov barrels.
AR15 Guy they also had keyhole problems so had to increase the twist rate in the ksuykha
Wish he would have tried the M855 out of the 20" 1:12 can only imagine the damage would be more
@Commies Get Rittenhoused to be fair the 105 didn't replace all the 74U out there, because it's not that affordable, even for the Russian government
Shooting 62gr ss109 out of my bushmaster m17s 21.5” 1:9 vs fostech faxon barrel 16” 1:8, melons explode considerably more when hit from the bushmaster.
The 55 grain bullet out of a 1/12 20” barrel was impressive. Palmetto now needs to add this to their kits (although it’ll never be in stock, like most everything else).
@@rodiculous9464 Yeah, you're "limiting" yourself to THE most effective load, at least at closer ranges. I'm always dubious when someone makes radical changes away from the original loading for any cartridge. Radical load changes are usually the result of attempts to make the cartridge into something it was never intended to be. The 5.56 was never intended to be an 800-yard cartridge. It was designed for close assault, which rarely entails ranges of longer than 300 yards. The M193 load out of a 20-inch, 1:12 barrel is simply devastating.
@@careylymanjones why would a 1:12 twist be more effective than a 1:7 twist in the same barrel length for a 55 grain? More energy going into velocity rather than spin? Or less stable bullet so it tumbles sooner?
@@SR-wz2iv someone correct me if I'm wrong, but to my understanding, it does create more velocity and just enough spin to stabilize until it hits something. Then it tumbles and wreaks havoc. But The rule of thumb is The heavier the bullet, the more twist you need to stabilize it.
@@SR-wz2iv Less stable bullet. M193 in 1:12 barrels was famous for devastating wounds in CQB. You gave up some long-range accuracy, but the M-16 was designed to be a 0-300yd rifle that could reach out to 400-500yds in expert hands. Fast-twist barrels and heavy bullets are an attempt to make it a 600-700yd rifle. This is arguably useful in the hills of Afghanistan, but most of us aren't in Afghanistan. Making 100yd shots in legitimate self-defense is pretty rare. I don't think I've ever heard of anyone ever needing a 300yd shot in self-defense.
Giving up the devastating effect of the light bullet/slow twist barrel combination for the dubious benefit (for civilians) of extended range seems unwise, to me.
My rule of thumb is that the original bullet weight in any given cartridge is probably best for the original purpose the cartridge was designed for. And if your needs change, you may be better off looking at another cartridge, rather than screwing up a good cartridge by trying to make it into something it wasn't designed to be.
@@careylymanjonesWhile everything you’re saying is correct I’d take a 77 grain bullet over a 55 grain bullet for self defense it’ll have a considerable advantage in muzzle energy even say a 16 inch barrel 1/7 twist with a 77 grain OTM would be absolute devastation obviously even worse with a 20 inch barrel
I'd like to see a Part II comparing the results of a 10.5" modern pistol with different bullet weights, especially some of the newer, heavier stuff like the 77 gr bullets.
Thank you, and anyone one helping you, for this presentation. I especially thank you for the respect shown to Paul Harrell and his crew. Both channels give outstanding quality and entertainment. BTW, this 4 tours 11B can attest to your results. The 20" barrel is better for either round regardless of twist rate.
Love the ref to Paul’s “Meat Target” love both channels, you guys have best content on UA-cam and are my go to. Keep it up great video thanks
I have been waiting for this test! Josh and Henry are planning to compare the 1:9" twist to the 1:7" twist in 16" and 20" tubes with M193 but haven't got to it yet.
Paul Harrel has done a number of comparisons of various AR configurations, including a couple comparing 20" and 10.5". Those results are surprising!
@@petesheppard1709 9 Hole Reviews has brought up the issue of the faster twist "over stabilizing" the lighter pills. I have inquired and they say they are going to compare 16" and 20" barrels with 1:9" twists to 1:7" twist rate tubes with different weight bullets
@@dbmail545 Thanks! I'm looking forward to it. Sometimes there seems to be duplications by different channels, but the varied results are very interesting to consider.
What would be really interesting would be a comparison between 1:14 and 1:7; where they started and where we are today.
Somewhere in the lands of Kentucky, a man who knows what time it is must be smiling. 🤣
Sheppard When Tim starts kicking eggplant, is when shit will get serious 😂
Yes I am.
@@johndaugherty4127 me too
🍆💥
This might just push me to pick up a retro 20" AR from Brownell's.
Yeah, that crossed my mind as well.....im going brown.
No desire for a retro build but a 20" 1:7 to spin some 77s would be a nice build. Me thinks maybe Odin Works.
@@bmstylee 1:8 is more universal. And probably 18" is just fine (certainly much better than 14.5 and not much worse than 20")
Just built one myself. It's a hoot to shoot :D
@@ZhuJo99This comment chain is speedrunning the degeneration process from the SP-1 to the M16.
Nyet; Rifle is fine.
Fun fact: M 16 was first adapted by USAF to replace M1 and M2 carbines for USAF base security. I think it was General Lemay who got the M16 in the door
Update, military went to short barrel for easy movement in rooms. In my day, m16a2 was used. Room clearing was done point shooting. Not shouldering the weapon, or scope aiming. No problem hitting center mass target. Less time. Easy to swing on next target without having to move your head. Just trained in old school. Love to find a cilivan m16a2, love the sights.
Lol.
you can if you have 40000 dls
I have ARs in SBR, 16”, and 20” lengths. The SBRs and carbines are my day to day truck guns, for the simple reason that I’m old and fat, and they weigh less and are handy. But if I had to go to war, my 20” A4 is the one I’d want to go to war with.......iron sights, bone simple, reliable, accurate, and still not too heavy. I love a 20” AR.
I hear ya, got several lengths myself. My 20" AR has a SS match grade barrel, 1/7.5" twist with a 1-6x, shoots 77 grain with excellent results. I'd like to get an A4 at some point, for the same reasons.
Got some Speer 75 grain gold dot soft points for my shorter AR's. The 14.5"(pin&weld) with irons is so simple and light, got a LMT rear sight.
I'm getting old(er) and fat(ter) too, I am an advocate for learning to use irons sights but I am becoming a fan of modern choices in optics. with the iron sight option of course.
recondo886 Yeah, that’s the same reason why I have some sort of optic on all of my other ARs, as well as on every other kind of rifle I own. I just like keeping my A4 as simple as it can be, with the carry handle sight and everything. I used to have a 4x32 RCO ACOG on it, but the short eye-relief didn’t work that well for me with the fixed length A2 buttstock. So that’s why I converted it back to the iron sights. They just work, even if my 68 yr old eyes can’t see as far as the sights will shoot. I ended up putting the ACOG on one of my carbines. But even then, it seems like the primary advantage of the ACOG these days for me is the relatively light weight. I find a 1-6x LVPO to be a lot more easy on my eyes.
I think you just sold a whole lot of 20" 1:12 twist barrels.....
As he stares with bedroom eyes across the room at Faxon......
@Neil Carpenter But well worth it.
@@ourvaluesarewhoweareinadem4093 Agree, i have 2, a 16 and an 18 inch, Love Faxon products!
@@DefZen343 Oh yeah! I refuse to build with anything else at this point. Their pencil barrels are just wonderful.
Not when they find out what a 77 will do from a 20 inch with 1-7
20" Master Race nods knowingly.
What?
With a 1:12 twist, of course.
Amen
I went through basic and 6 years active duty with the M16A1 rifle. I feel the sights on the A2 are a good upgrade.
Did the M16a1 have the aperture sight in the rear?
@wyomarine yes, the peep sight is what I meant by aperture. The "a2" rear sight on my ar-15 has adjustment knobs for windage and elevation.
This is interesting, Mac, especially the last one with the meat targets. Unfortunately, it's been done before (hell, I've done it myself but without a hi-speed camera) so I was pretty sure what the results woukd be.
Remembering back to the dust-up in the late 60's - early 70's (and trust me, I remember it well, although I was never in the military) the main complaints I heard or saw in print were regarding the ammo's ineffectiveness were a bit farther down range than 25 yards. From what I was able to gather, it seemed the major complaint was at something beyond the 125 yard/meter range, after the bullet had "gone to sleep" - we all know that rifle bullets settle or stabilize at around that mark. I have confirmed this on some of those big mature southwest jack rabbits... hit up close, under 100 yards, and those 55 gr. FMJ's blow the snot out of them. Hit them farther out, beyond that 100 - 125 yard range and the bullet simply pokes a hole. Granted, even a big jackrabbit isn't large enough to really test a bullet, since they are only 10 - 12 pounds and relatively thin skinned & bodied, but the .308 ball ammo out of an HK or FAL was much more devastating out to 250 yds. or so. Shots beyond that were a bit difficult on such small and usually rapidly moving targets... not that we didn't try, of course. I did blow one up pretty good at a stepped off 400 yards but it turned out the bullet hit under the hapless bunny and sent gravel shrapnel into his soft belly, opening him up in a most spectacular way.
Ok, so it's time to put the the legendary accuracy of the AR platform to the real test! Set those melons up at 150 and 200 yards and repeat the tests! We've seen you paste those steel targets over and over again with the AR's (even AK's!) at that range so we know it can be done, even if you have to scope the rifles to get a more precise shot on target. That will be a much more valid test than shooting at 25 yards.
Personally, I've always considered the AR platform (1:12, 55gr) as a 150 yard gun, unless using my 20"/1:7, stainless, bull barreled, 10 pound upper... then it goes out to maybe 300 yards with the right ammo. It's super accurate but I damn sure wouldn't want to lug the thing around with bullets coming back at me!
Thanks for all the work you put into the vids, I well aware of how much effort goes into making these video's... just so we can all sit back and Monday morning quarterback!
Cheers,
jc
Re: "Personally, I've always considered the AR platform (1:12, 55gr) as a 150 yard gun, unless using my 20"/1:7, stainless, bull barreled, 10 pound upper... then it goes out to maybe 300 yards with the right ammo. It's super accurate but I damn sure wouldn't want to lug the thing around with bullets coming back at me!"
Your observation tracks with the design parameters of the weapon, and its intended use. The whole point of assault rifles, as a class of military small arms, is that they fire an intermediate cartridge, one whose size, range, power and weight fall between those of a full-sized rifle on one hand, and a pistol or SMG on the other.
During the Second World War, it was noticed by several militaries around the same time (Germany, USSR, U.S.) that there existed a need for a weapon which was intermediate in power/range between pistols and SMGs on the low end, and full-sized rifles and medium machine guns on the higher end. It had also been seen in action that most wartime infantry small-arms use occurred inside 300 yards/meters (as the case may be).
That range envelope of about 300 yards is precisely the one in which an assault rifle like the M-16 was designed to function optimally. Stoner's team designed M193 55-grain FMJ/Ball to fragment at sufficiently high muzzle velocities, from roughly 2700-2800 fps and up. Using that figure as a benchmark, the 20-inch barreled M16 was optimally effective inside 150-200 meters, and the shorter barreled carbines somewhat less so.
The Army and Army Ordnance went back and forth, and the former eventually requested that the weapon be "effective" out to 800m (fixed carry handle sights) or 600m (removable carry handle sights). "Effective" in quotes since the ideal range envelope was well inside of that using M193 or the later M855 ammunition. In plain language, the slug was still potentially lethal out to the limit of the sights, but less-so than at ranges inside 200-300m, or typical combat ranges.
The trade-offs arrived at by Stoner et al. were part of what it took to make a weapon compact and light-enough to qualify for Army requirements for the light rifle program - which stipulated a select-fire weapon using .224-caliber ammunition. But Big Green wanted it both ways, which is why the program had elements of both assault rifles & intermediate cartridges in them, along with holdover ideas such as being able to engage targets at more-traditional rifleman type ranges out to 600 or 800m.
Later advances in ammunition design dramatically improved the performance of the legacy AR15/M16 system, including not just use at close/medium range, but out to 800 yards or more. Mostly, these improvements dealt with using a heavier slug and a faster rate of barrel twist to stabilize such long and relatively heavy projectiles. Today service rifle competitors routinely use 80- or even 90-grain bullets for 1,000 yard matches, and tactical personnel often use 75-77-grain projectiles even at more moderate ranges.
Tim has become the Gallagher of the firearms world....
Reason I built my rifle with a 20” barrel chambered in .223 Wilde with a 1-7 twist.
Nice ...
I guess now we need the same test with FBI ballistic gel
1:12 twist barrels now out of stock. Great video
In the early 60’s my dad worked as a gunsmith. Some guys in the shop started to talk about a new rifle and ammunition going to be used in vietnam. They showed some pictures of the bullet effects. One picture was of a dead guerrilla with a little hole in it’s chest and one when it was rolled over. It’s heart fell out of the hole in it’s back.
Holy fuck that's brutal.
I would like to see how the shorter fast rotation 14.5" platform does with the 77 grain MK262
Ditto, 77gr from 1/7
Yes, and in both 1/12. & 1/7.
@@donski1519 i doubt it would stabilize a heavy bullet in a 1/12
@@donski1519 1/12 wont stabilize it. Paul Harrel has a video up showing it won't even stabilize green tip.
ua-cam.com/video/bKQizbg1zBw/v-deo.html&ab_channel=PaulHarrell
Very interesting indeed. I may swap to the longer barrel now after watching that. So, can we see a similar test with 300blk barrel lengths and different twists? Please... when you can of course. 😆
@@Bender_B._Rodriguez pretty cool - thank you
You don’t get as much of a velocity improvement with .300blk as you do with 5.56. Mrgunsngear has a video on .300blk velocities with different barrel lengths
Hasid lafre the 7.62x39 is just the Russian .30-30 ;)
Yeah I'd like to see the 300 out of the 9 and 20 inch barrels with the 1n12 and 1n7 twist because you hear all the time the 9 inch performance is better.
@@echofoxtrotwhiskey1595
Correct, but I do believe the Hornady SBR 5.56 has faster burning powder to make the performance a little better, but by how much I don't know and honestly for the price, not as cost effective as just having a longer barrel to begin with.
But the 5.56 was designed to wound it's not capable of lethal damage...
/sarcasm
@lilbeserk Yeah and the US was fighting off human waves in Korea, guerrillas who couldn't expect medvac or get taken to a proper hospital in Southeast Asia and if push came to shove, a Soviet Union that would not have the money to send helicopters to save every screaming Ivan.
If the morale was reduced from screaming, they'd probably just put a bullet in them themselves. And if they did live, they'd come back a few months later to kill you.
5.56 was chosen because the US expected to fight Soviet steel beasts and thus every man would need to be carrying a LAW on his back. Lighter ammo would be needed for those conditions. And when special forces used 5.56 in Vietnam after they ordered AR15s, they did note it was _VERY_ deadly. Let's just say, the M16 was pressed into service because it didn't leave people screaming.
Exactly. since Vietnam special operations units have had their choice of weapons, guys were literally fist fighting over car-15's and stoner63's and would trade a nice watch for a half arsed cobbled up 30rd mag, not many guys chose m-14s and m 60's 🤔, occasionally somebody preferred an AK, but once again not a full power cartridge "battle rifle". in my reading/listening most special operations vets rave about the m-16 being great, not a "underpowered jamming plastic death sentence"
@@8166PC1 bulshit
Wonder where that bullshit started?
@NOThotsquidjunk There are people in the replies to this very comment agreeing with your clearly sarcastic repetition of a commonly repeated, but patently false, assertion.
The requirements for 5.56 that the military was looking for, as outlined in their trial reqs, was a.) .22 caliber catridge b.) much lighter weight so more could be carried c.) was softer shooting so it was capable of controlled full auto fire comparable **D.) equal/better wounding to/than the 7.62 NATO at the distances considered relevant for modern combat (doctrine shifted to 300 yards and nearer)**
I.E they ordered up a cartridge with equal-ish lethality to the .308 that was smaller. When they finally accepted the 5.56, it was reported internally to have EQUAL OR BETTER TERMINAL PERFORMANCE/WOUNDING CAPABILITY to current 7.62 NATO rounds. So not only was it ordered as specced to comparable lethality, it was adopted using data that showed it was just about as (or even moreso) lethal than what they currently had.
Allow me to repeat: They put out a request for a .22 projectile with the requirement of comparable terminal performance (within 300 yards at least) to .308. They were given data and reports that suggested this new round was actually more lethal than the .308 in many circumstances. And they adopted it.
Regardless of the truths of .223/5.56 vs 7.62 NATO/.308 and their terminal effectiveness, those are what they thought they were gonna get, and once they got data saying it did that, they adopted it.
If you accept the premise that .308 is not designed to wound, then you cannot argue the 5.56, BELIEVED (true or not) to be its EQUAL by those who adopted it, was designed to wound.
Back in the late 1960's the M16 with the one and twelve twist - twenty inch barrels shooting the fifty five grain M193 bullets were very devastating on soft targets in Vietnam. These bullets were known to start spinning when it hit the soft targets, spinning and yawning, then exiting in different directions. Causing massive wound damage ! A very devastating bullet for combat !
Rather than being “unscientific” tests, I’d call them qualitative! Excellent demo! No wonder the original M-16 was so devastating to the enemy!
The early AR-15s with the 1 in 14 twist developed quite a reputation in Vietnam. Unfortunately testing showed that it wouldn't stabilize bullets in sub-zero weather so they had to go with 1 in 12, lessening the wounding effect.
My 20" is my favorite. I don't see why they aren't more popular. Smooth shooter.
I do believe they are having a resurgence tho. Quite funny to me seeing people with their Uber short 8" ARs. I know compactness is nice but your losing Ssooo much for it. Hence why I'll always be a 20" man.
@@Patriotusa44 I believe an 8" barrel produces almost exactly half the energy of a 20". It's closer to a PCC than a rifle at that point. May as well be an entirely different caliber compared to what 5.56 is capable of.
Because they watch and play dumb videogames and movies
Loved the shout-out for Paul Harrel, would love to see a collaboration of both channels.
Well, I'd love to see a collaboration between MAC, Paul Harrel, Iraqveteran8888, Brandon Herrera and Garand Thumb, but last time I checked something that entertaining and informative was one of the signs of the apocalypse.
Years ago on a well known AR site myself and a few others argued this very thing 1/12 55gr AR 20" is best AR. It didnt catch on.
the "A1" rocks.
Yeah it did to some extent. I made it a point years ago to acquire an original pre-ban with 1 in 14 twist long before the current retro craze.
It was absolutely the best for jungles. The tighter twist, better coefficient and heavier bullet were developed to reach farther. It was needed for the more open terrains of the last 30 + years.
i know that ar site, and those people are idiots. there is something else 55 grn fmj does at close range.....holes 1/4 inch ar500.....which m855 has a hard time doing do to lack of velocity.
First introduced to the AR-15 weapon system was thru magazines back in the late 50's. Did not see any in the gun stores
until I came back from Vietnam in 68. Joined the USAF in Feb of 64 and went to Turkey. Our commander had any troop being sent to Vietnam go to the Armory and get familiarized with the weapons that the AF had available for us at the time. That
included everything from the .38 revolver up to Ma Duce. Got trained on how to handle, use and shoot the M-16 and especially how to insure it was cleaned after usage. They were reports of problems with the weapons system filtering back to us at the time. The Gun Smith told us that when we went thru the US on our way to Nam, we needed to pick up a cleaning kit for a .22 rifle and he showed us the bore brush we needed also. I bought 5 of them to take with me. Glad I did as cleaning kits were nonexistent when I got there in early 66. Had some friends, in the USMC, that were stationed across the street from us at Danang who I bumped into. I gave them 3 of my cleaning kits with the bore brush. shortly afterwards they were
issued cleaning kits to help maintain their weapons. Massive difference in reliability of the weapon system. Many loved the
weapon but many hated them and said in the heat of battle sometimes they would grab a AK to use as it held up under any conditions they encountered. As I was not a combat troop, I cannot not deny what they said and merely repeating what I was told at the time. All we did was go to the range and get to shoot the weapons that were assigned to our Unit and then bring them back to clean and return them to the NCOIC of the Security Policed det assigned to us. Currently I own a Ruger AR-556 with a 16.5 inch barrel and am looking at locating a upper with a 20 inch barrel. I like th ballistics I've see with it better.
Great video. Many years ago as I entered rifle ammunition reloading, I started working up handload recipes for .223 Remington and 5.56x45 mm cartridges. In my research of the projectiles, I discovered that the M193 full metal jacket boat tail bullet with cannelure must accelerate to a minimum muzzle velocity to provide optimum performance. The M193 when fired at it's designed muzzle velocity is designed to tumble after a short penetration. The centrifugal force produced by the tumble effect should break the bullet into several smaller pieces at the cannelure enhancing the hydrostatic shock within the target. The M4 rifle with the shorter 14.5 inch barrel may have difficulty extracting the full potential of the M193, M855, or SS109 projectiles. Having said that, the M4 is still a terrific, reliable and accurate firearm.
lovin' the slow mo, I hope you keep the slow mo segment for similar type of videos.
I would also like to see a test of the meat target done with the 14” pinned barrel for comparison because 14” - 16” barrels are more common today than 20” barrels. We thank you for all the testing though, as do the ants and other insects.
Although not scientific testing, still the question begs to be asked; which would you rather be shot with? And the answer is: not a damn one of them!!!
I still cease to be amazed by Stoner's brilliance.
Nice shout out to Paul Harrell,
This just confirms what I knew in the Marines and why I still to this day love my A4 over the M4 they offered me when I was in.
This goes back to what we have known for a very long time. Push a round as fast as you can and give it just enough twist to stabilize it. If you have to compromise on one side it is better to "over stabilize" than under stabilize as accuracy is what's most important. Do the same test but for accuracy instead of terminal ballastics and it will confirm this.
Also that KS for giving a shout out to PH. Your a stand up guy.🙂
Lesson for the day. Eugene Stoner got it right the first time
Maybe the right choice in 1959 since practical, affordable body. armor for front-line troops didn't exist, but today personal body armor that can stop m193 is more or less universal.
@@madeconomist458 and you think a 14 or 16 inc is going to fair better?
@@Sujamma_Enjoyer M855 out of a 14.5 inch barrel will penetrate level 3 UHMWPE armor, but m193 out of a 20-inch barrel would not.
@@madeconomist458 ok? And? Use a different ammo type
@@madeconomist458ur lying
Being in the Marines in the early '70s I was very familiar with the a1 with 1-12 twist, 20 in barrel, m193 cartridge. A good combo out to 300 yds give or take. My understanding is the m855 and reduced barrel twist added another 200 yards or so to the rifles accuracy.
Fun video, keep it up! Y’all should add the 77gr OTM from black hills or IWI next time.
The 14.5 with the 1:7 twist would look alot letter
I'm surprised the M193 did worse on the melons than the M855 with the 1/7 twist barrels, I guess it didn't destabilize as fast as the M855 but in a real life meat target the difference would likely be negligible.
Love the "test." Definitely interesting results. Would've loved to have also seen both rounds through a standard civilian 16" carbine.
Thank you for doing this comparison. Been thinking about a 20" build for 55gr since it's the cheapest and most common (usually) and have been trying to figure out if the slower twist rate has better terminal performance. Nobody wants to talk about anything except "1:7 sbr's". Info like this is hard to find.
Thanks again
no one wants to stock 1:12 any more either they are hard to find in mass he'll even 1:9 are harder to find but 1:7 16in are overly abundant
I feel confident if I’m ever attacked by a bunch of watermelons my AR will be able to protect me.
Guns don’t ‘splode watermelons; people ‘splode das melons.
Watermelons with armor plates and your done for...
This why I love my happy medium.. AR-556 MPR w/18" and 1:8 (w/ trick 5R rifling)... on an elite 452 trigger. Wooo.. She's pretty sweet.
I have a SP1, very interesting!!
Thanks for posting and the effort it takes to film/edit and upload
No "yeah-buts", no caveats, no Shatner-esque ... ... pauses?
I went with an 18” 1/8 twist BCM 410 barrel, in an attempt to combine all the best factors and features.
Did you find it to have better results? I'm running an 18" 1/8 as well.
I want a 20" 1 in 12 fixed stock sooo bad.... But they're gone... And there's no ammo..... I don't recognize this country anymore 😭
On the off chance you live in new England kittery trading post in Maine has .223 in stock on 500 round flats
Google parts kit. They are out there..
Welcome to the ussr :/
Brownells BRN-Proto 5.56 20" 1-in-12, In stock. Geoff Who notes it doesn't have a forward assist or a charging handle. Does have a dust cover.
Buy the parts, make one! Building a regular flat top AR is one thing, but building a stripped fixed carry handle upper, omg so much more fun and lasts longer than a half hour.
I've also had good performance with 1/8 and 1/9 twist rates in a 16" setup. The 1/9 twist actually has performed far better than I expected.
The results of this is awesome. I absolutely love my A3 style m16. I absolutely love the fact that this kind of proves what I have heard some combat vet say which is the longer barreled AR-15 / M16 are actually much better. I just wish you could get your hands on m855 better right now. With all this ammo shortage and craziness going on finding ammo's getting hard.
1 year later, if you have Academy Outdoors near your area, they have pllllleeeennnnntttty of M855 Green Tips on their shelves to the point it’s basically the only 5.56 they have! I got their 200 rds range pack here for my Daniel Defense MK12…..I know it likes 77 grain match grade rounds the best but damn it! At $35 for 20 rds, it’s too expensive so the 62grain green tips will do. I do know not a lot of indoor ranges will allow you to shoot the green tips because it’s steel core makes it a semi-armor piercer but the one near me do allow it so I go there a lot so yeah, it’s out there if you know where to look.
I think it is “Hydro-dynamic” shock. Some have said that it is Hydraulic shock. Hydro-static refers of a pressure that is essentially “static,” or constant. FWIW
Hydro-dynamic shock is when water abruptly slows down, like the water-hammer effect in your house pipes.
Hydro-static shock is energy being dumped into static water, forcing the pressure wave to propogate through it catastophically.
Excellent video. It would have been interesting to see how the M855 would have performed using the SP1 rifle (1:12 twist).
Exactly! I was disappointed this wasn't considered.
I fell and landed on my side from 30 feet. my lungs were fully intact A watermelon falling from 30ft would leave a big splat. Just throwing some perspective out there for the tissue physicists.
How much velocity is lost on that bullet after it goes through the clothes and rib cage?
I imagine the hydrostatic shock on lung tissue is pretty minimal past 250-300yds.
Let's be real for a second: all those wounds would be lethal regardless.
@lilbeserk oh I agree.
This requires more testing. How fast can you get to Portland?
Yeah well so would an equally well placed .22 LR. at only 25 yards. What happens at 300 yards? The difference could be a clean pass through verses a devastating wound.
Yup. Another important fact is what the bullet has to penetrate before hitting flesh. In Vietnam many enemy troops had on a shirt or smock. Fast forward to today and many are wearing load vest and mag pouches and other gear. That is why in gel an important but often overlooked metric is the neck length. A long neck that expands violently is going to be better at gear penetration where a short neck and consistent expansion is going to be a better hunting round. Because animals don’t wear coats and mag pouches. But hunting would be more fun if they did.
@@ryanpm4460 Don't forget also that one of the main complaints about the efficacy of the A1/556 in vietnam was how it struggled with brush. Of course it's devastating if it tumbles the second it touches a person, but it's not so devastating if it spins off into nowhere after clipping a big leaf
If you pattern that on a piece of paper, most people don't realize with that slow rate of twist that bullet is coming out of the barrel and turning sideways to keyhole. That's why it destroys the watermelon. That rate of twist does not stabilize the projectile and it hits sideways.
First video of yours I’ve watched. Loved it. I’d like to see a comparison damage of the SP1/M855 ball to the 77 grain bullet from a 16 inch barrel with a 1/7 or 1/8 twist. Thanks for your effort here.
Hey Tim are you still planning to compare the BCM MKII upper to your MK12 in terms of accuracy/rigidity? I just got a BCM MKII and I'm interested to know if they truly are more rigid. You're the best!
The thing about this test is that both of these rounds are known to have pretty wide variations in yaw depth, and that's the key factor in what you are wanting from these
The twenty inch A1 was also very easy to shoot. It is also lighter then it looks. For an Infantry men in Korea the twenty inch with an optic would be ideal.
Excellent informative content. Thanks for making this demonstration.
The xm193 ball was designed to perform with a 20" barrel with the right barrel twist. Thats why guys had issues in Vietnam when they decided to chop the barrels with the CAR-15. The Russians were a little smarter with the 5.45 x 39mm because instead of focusing on barrel twist and length to get the bullet to perform right. The Russians just hollowed a small space in the top of the 5.45x39mm so no matter what barrel length or velocity they are shooting at the bullet will perform every time and get that tumbling "Yaw" effect . Luckily however we now have the M855a1 it penetrates more then the green tip and fragments like the XM193 like at optimal performance even if you shoot it out of a shorter barrel.
I don't think the choice of targets was accidental. If I remember correctly, a watermelon was shot at an "informal" bbq by the prototype rifle and that convinced a general with the U S Air Force to give the rifle a chance in military service.
General Curtis LeMay.
USAF Chief of Staff Curtis LeMay wanted the new AR15 so badly that he nearly antagonized President Kennedy and Secretary of Defense McNamara into firing him, he badgered them so much for the funding to buy them. The USAF didn't adopt the then-new M-14 service rifle, as LeMay felt it was unsuited to the mission of his air police and base security personnel. However, when an AR15 was demonstrated to him at the now-famous picnic and he had a chance to fire the weapon, he was sold and thereafter worked very hard to get them for his service. LeMay's requests were turned down initially, but after U.S. Army Special Forces advisors had used the weapons successfully in SE Asia in the early 1960s, Kennedy and McNamara eventually relented and allocated the money and the Air Force got their rifles.
@@GeorgiaBoy1961 Too bad they decided to switch powders and make changes that caused reliability problems. The government just can't help but mess up a good thing.
This is why i run a 20" w 55gr. Sadly no 1/12
I know everyone calls it "hydrostatic shock". I don't have a degree in engineering, but I remember my physics class. The bullet is moving! Statics is the study of non-moving forces working against non-moving items. If anything, the shock is hydrodynamic! Yes, I'm right, look into it, go ahead and argue with me on this!
rifles are capable of accelerating the entire universe relative to a bullet
I do have an engineering degree so let me clear this up for you. You’re correct that the study of statics vs. dynamics is physics of forces in stationary vs. moving bodies, but this experiment is hydrostatic forces which is a different study.
Hydrostatic Pressure is relating to or denoting the equilibrium of liquids and the pressure exerted by liquid at rest respectively.
Hydrostatic shock is a controversial topic usually in reference to hydrostatic pressure from a bullet impact and the results due to the pressure wave. So hydrostatic shock is the correct term here.
I took stills of each barrel combination w/ bullet weight as 1) striking watermelon target 2) at "max explosiveness point [?]) on target; then created a layout of the stills to allow comparison of each demo. Damn, what a "jarring" visual reference to allow someone to look at the effect of what their particular barrel/bullet weight combination has on terminal performance. Thank You for this presentation, Mac!!
For this reason, Brownell's should keep producing their retro rifles, in that wonderful 20" barrel configeration, with the 1/12 twist rifling!
Even though the 55gr out of the 14.5” was less than all of the others, that still seems pretty deadly.
The bugs around that table are like "manna from heaven"
Lol
Where do I get a "Kill a Commie for Mommy" shirt? Asking for a friend.
Just go to Portland or Seattle I hear they have lots of "Commies" so you could take their shirts and you would even be helping their mommy's get them out of her basement. I hope you like the color black because that's all they seem to wear.
Ballistic ink
You have to earn it like prison tattoos lol
Visit some nazi loving site
My recommendation is to use gallon milk jugs full of water, but you could try to make jello in a few and shoot them.
The milk jug doesn't explode like the watermelon, but gives you a good simulation of what a bullet will do. I used to have a CUR-2 in 5.45x39mm. The milk hug showed the projectile going out sideways once I pieced the split back together.
The reports of crazy aggressive wounding were actually with the earliest 14 twist barrels used before the Ordnance Corps got their mitts on the AR and added the fwd assist and screwed up the ammo. Rumor has it that the 14tw barrels were produced on worn tooling that produced actual twist values even slower-- perhaps even 16 twist in some cases.
Green Mountain makes a 14tw A1 barrel I'd love to try.
Moral of the story: Tape a ham to your chest while in combat, it might just save your life.
Just wear some phone books
@@johnaranjo2059 lol