A friend of mine got a job with a small suppressor company and is starting his firearms journey. I shared this video with him because we’re all learning together.
Good for him! I have a Cerakote shop in my garage and I'm a collision painter by trade. I consistently went to three local gun stores to get a job and get out of the Body Shop rat race and I couldn't get a job with no one. I brought 3 examples of my work along with my firearm knowledge..........nope. Apparently God was telling me some.
@@JohnnyBravo02 its been adventurous. Its not like spraying PPG. The flash and bake times are weird. I'm still learning. I am getting better though. Have a blessed weekend brother.
@@tangomantactical glad to hear you’re improving! You know how it goes, it’s all about repetition and consistency . You have a blessed weekend as well bro
You’re missing a big variable here. As a rule of thumb, when velocity doubles, the density of the substance essentially quadruples in relationship to the projectile. Think about jumping into water from five feet vs fifteen feet. Thus, when the faster bullet hits the medium, it is met with greater resistance than a slower projectile, which affects penetration. Which affects the temporary and permanent would cavity and also affects incapacitation of an animal or human (think blood pressure changes and nervous system shock, etc.)
I am absolutely mesmerized by your intense detail with all of your videos!!! And have to say your voice should be on National Geographic!! Your detail to attention is unsurpassed to all other videos. Thank you for what you do! Please keep the amazing content coming!!
1:5 or die. That rattler impressed me. With the short barrel I’m shocked it performed that well. Even with the twist rate I didn’t think the velocity would be enough to get the projectile to expand that much.
Yeah I agree the Rattler was the big surprise and eye opener of the bunch. I’m definitely gaining a lot more faith in that firearm. Thanks for watching.
@@AlabamaArsenal one thing I have seen in other gel test it is possible that the mini fix expanded faster which would cause it to slow down quicker and stop shorter than the honey Badger the velocity would be similar but just that extra inch in powder burn could cause that to happen
@@AlabamaArsenalIt's interesting that the Honey Badger penetrated so much more than the Rattler. They have the same twist rate and the HB barrel is only .5" longer. That's a big difference for half an inch!
I’m more interested in how the twist rate affects the rifles accuracy more than the minuscule amount of energy increase it delivers. If the group size cuts in half.. say, 3 MOA to 1.5 MOA, then the higher twist rate means something to me. If it does indeed stabilize heavier bullets to the point accuracy is much improved, it’s a winner.
Supposedly twist rate and accuracy isn't a clear cut thing. For example perfectly stabilizing bullets only works for a specific range as the spin slows over distance. Usually testing is only done at 100 yards so all data around stability is only for this range. When you get out to long range such as 800 yards or further, the bullet is generally unstable and this can cause wild shots when it punches into the transonic speeds. In contrast fast twists that overstabilize bullets may cause wider groups at close range, but because the bullet slows down the spin at longer ranges and still has more spin than a conventionally stabilized bullet, the groups at long range are actually tighter.
My degree is in Biology, not physics, trauma surgery, or ballistics; so I am far from an expert. Evaluate my opinion accordingly. My main takeaway so far is that the 1:8 twist rate appeared to have created a larger temporary and permanent wound cavity. This is what I think I want as it demonstrates a greater energy dump in that first 14 inches. That is where I want the damage on a soft target, yes? The greater angular momentum caused by the higher twist rate seems to be going towards more penetration. The round is conserving more energy that is going towards deeper penetration, dumping that energy over a longer path, amount of time during that longer path, and dumping more of that energy out of that target "ideal wound" area. What I would love to see is a comparison from identical, or near identical, barrel lengths with the only significant difference being the twist rate. A longer barrel may mean a slightly higher velocity, and a higher twist rate may contribute to greater accuracy over distance (?), but I would love to see something closer to an apple to apple to help with this specific debate.
The longer barrel actually caused more expansion. Although it has a smaller diameter in the end because of the bullet design it hit the same expansion and then peeled back further. In my opinion the extra speed caused more energy dump resulting in less penetration. Less speed more fmj like penetration.
Majority of subsonic loadings are designed for 16" barrels, the shorter ones will be slower, regardless of negligible loses in velocity there is a loss in velocity. I wouldn't go under 15" but you guys have silly nfa hoops to jump through to avoid SBRing things. The perfect 300blk is a 15" carry handle uppered rifle, gives you two sets of sights and 2 zeros.
Jason, I agree that he wasn’t looking at the right things. The distance from the front of the gel to the expansion is more telling than the depth into the gel.
thats the way Sig made it. 5.5" barrel for 223 and, 5.5" barrel for 300bo. i agree with what your saying but, again Sig designed it. they do not make garbage. i shot 20rds threw it and it shot like a dream. i definitely would not want to get hit by it, regardless if it doesn't expand or the velocity is way off. this firearm was strictly designed as a back pack, vehicle, by your night stand. thanks for watching the video. Subscribe! i have more content coming this weekend. God bless.
Been saying this for years, the final measured expansion is not always the maximum expansion. Both are valuable data points but need to be defined separately.
My favourite caliber. Thanks for this series. Can't wait for the supersonic testing video. I love my rattler, and since I don't have a chronograph yet I'm very curious to see the velocity with supers from that barrel.
Alabama Arsenal’s videos are not only informative but they are so Zen to watch!…best background music, video editing and narration on the interwebs 🤘🤘🤘😎😎😎
I’ve enjoyed watching your channel since the beginning and how you guys breakdown and diagnose how it works in layman terms for a simple folks, I wish UA-cam scrubs had a four or five star rating because y’all deserve at least a 10 on every level, thanks for sharing your knowledge, 🙏
Great video. Thanks. I have also tested numerous 30cal subsonic rounds. As most available 300blk rounds don't expand subsonic I have a found a slower twist rate to create a much greater permanent wound cavity. There are very few expanding 30cal subsonic bullets available outside USA. I have found "minimal stabilization" performs much better in 30 subsonic with non expanding bullets. Even the Hornady 30 cal subsonic perform really poorly. I have found a 9 to 9.5 twist with over 200gn bullets to be ideal. They turn sideways immediately upon impact and cut a 1 inch plus wound channel nearly all the way through most medium game. I am certain the permanent wound cavity will be greater than what you showed in this video. Even the cheap Lee 230gr cast bullet will kill a lot better than any over stabilized jacketed bullet in 30 cal. I run the Lee 230 in a 9.5 twist and I doubt you will beat it's permanent wound cavity with expanding bullets. Cheers and take care.
@@WilliamHClarkiii what are you talking about? Where did I say anything about sloppy aim or not taking a clean shot. I'm tipping you don't have a clue about what I'm talking about. Brush up on some ballistic principles maybe.
I would love to see the DDM4 PDW with the 7” 1:7 twist barrel added to this mix. I do think that a 1:8 twist rate is probably too slow for subsonic 300 BLK. I personally opted for one over a Sig rattler. As always, I appreciate your time, effort and expense in making these informative videos.
I went with the DDpdw as well. Not a fan of how big the rails on the sig are. They just look uncomfortable. Also not a fan of folding stocks. Went with the sbr version ✊️✊️
I love my 10.5" barrel. With Black Hills 110 gr ammo using Barnes TTSX the velocity is around 2250 fps. This makes it a point and shoot gun out to about 300 yards. The energy is roughly equivalent to an AK with a 16" barrel. For such a small package it performs great as my home defense and truck gun.
One of the other guys mentioned V x density.. but I would like to point out.. a friend of mine, knows little about firearms and he wanted a.308 with a 22” barrel.. I recommend to him having a longer barrel would cause more drag on the projectile and would counter the pressure you’re trying to build. In other words there has to be a balance between twist and length in relation to the caliber being used..
Excellent video. Minor point (or maybe not), it would have been helpful to have seen chronograph numbers on these rounds. A good number of 300 AAC shooters are handloaders and velocity info is extremely important in comparing projectiles and barrel lengths.
Truly excellent video, one of the first YT vids I really feel I should pay for. I have a wide selection of 300BLK barrels, from 1:5 to 1:8 and 4.75" to 10" A few thoughts... 1. I've seen accuracy improvements that came with a faster twist barrel. Now it's not scientific, might be a better barrel in general, a better build etc. But it is the trend I've seen. 2. I'm VERY curious to see the effects of faster twist on fracturing bullets in gel. As far as I'm aware nobody is commercially loading the 198gr Lehigh and there's no other fracturing subsonic. But the 115gr, and 100gr offerings from Gorilla I'm very curious about. I'd expect the faster twist to so a lot with a fracturing bullet compared to an expanding bullet. 3. That then brings up, what is too fast for such a bullet? Put that 100gr Gorilla fracturing into a 1:5, will it explode, no idea haven't tried it yet. Might soon though, I have the pieces to try, just haven't put one in the other yet.
I don't think the claim being touted is that high twist increases penetration, as much as it increases terminal effect via expansion at a lower threshold. Increased expansion at lower velocity can mean LESS penetration, because energy dump is via drag/surface area interaction by velocity. If there's a speed limit on your bullet (subsonic) you can get more energy terminally at a given depth by increased spin (if the bullet expands) the petals make more rotations in a given distance inside the target, that's more total intervals surface area contacted/cut/crushed. But increased drag lowers overall penetration. It just so happens though that sinsonics don't have penetration problems, they have energy dump problems. They tend to not expand, and then ice pick, tumble once, icepick again, and then end up in New Jersey somewhere. The twist is supposed to translate that wasted energy into better expansion and initial terminal effect. But only as a side effect of the primary purpose: increased accuracy of extra long bullets at very low velocity. From watching Johnny's Reloading Bench you can see how much he struggled to get good subsonic accuracy when reloading, especially the larger bullets. *edit* there's another relevant effect of high twist in a super short 300 blk: supersonic effectiveness. As many tests on The Chopping Block have shown, lots of 300 blk loads don't expand properly in shorter barrels. They can approach or drop below the 1800 fps that 99% of .308 bullets are designed to expand at as a minimum performance threshold. Many will expand, but minimally compared with a similar design in a slightly longer barrel. But, especially with copper bullets, the twist seems to aid in the petals opening a bit more even as the bullet approaches that bleeding edge of nor expanding otherwise. MAC showed that his rattler gets fantastic performance from a 110 gr supersonic.
Love these videos! Content, information, filming, music, commentary, b-real, etc. are all perfect. I truly enjoy the Silencer School series. From someone who watches a lot of firearms videos from any and all channels, BRAVO 👏. 10 outta 10 would recommend!
Would've been great to test 1:7 twist 6/7.5 inch barrel as well, didn't even see you mention that twist rate... I know it's a DD, but 1:8 twist are normally the cheapest of 300 blk barrels. Great video!
Awesome video and testing ! Man sure wish I would’ve seen this video before hand, I just purchased a 6” barrel 300 blackout with 1:8 twist. I’ve been seeing more and more videos on that sig rattler and I’m impressed more every time, that thing is packing a punch for that short barrel with 1:5 twist rate, very effective and don’t be fooled it will reach out there and make 200 yard shots very accurately as was shown in military arms channel video. Prolly would’ve went with the sig over the 6” aero precision 300 I just bought if seen these test sooner. I’ll definitely be on the hunt for a 1:5 twist barrel for my gun as I do believe they make a huge difference especially in sub sonic. But thanks again for the awesome video
Super appreciate ya'll doing this test! Adds more evidence toward confirming what a lot of what the community believes in terms of maximizing the effectiveness of 300BLK and the types of results you can get from the cartridge. Very cool.
On twist rates. Spinning faster than required for stability is not required……..same as for tops. Bullets and tops are either stable or they are not. Spinning them too fast can tear their jackets apart and bullets spinning faster provide no real advantage in external ballistics. Also, Heavier bullets are necessarily longer. The longer the bullet, the faster you need to spin it to stabilize it in flight. It’s the bullet length that matters. Spin rate is determined by barrel twist and bullet velocity in the barrel. A short barreled rifle needs a higher twist rate as it generally produces less muzzle velocity. Heavy for caliber bullets (I.e. long bullets) need faster twist rates too. I’m not convinced that twist rates produce much evidence in terminal ballistics other than a marginally stable bullet will produce more damage as it tumbles after impact. Bullets damage by expansion and/ or fragmentation and also by velocity in the form of hydrostatic shock.
You've disproved your own argument, 300BLK subs are very long, in short barrels, at slow speeds. It's not really possible to over spin a 300BLK sub. The ONLY possible downside is maybe blowing up some fragile light supersonic bullet. The twist also clearly provided some terminal ballistic performance.
@@snek9353 The point that you missed is that the twist rate is to be used to produce the required rpm to stabilize the projectile…..not for any very small or imagined terminal effect. Long bullets and/ or lower velocities require a faster twist rate to produce the required rpm. Spinning it faster than the minimum required is a waste. So, yes, short barrel subs require faster twist rates…..for stabilization.
@@snek9353 I disagree with your assessment of the terminal effect. Nothing I have seen clearly demonstrates this. Overspinning is stressful on the bullet. Any deformation affects in flight.
Looks like a really well developed round. The cavity it leaves behind is nasty. Gel tests are always great to see. The more variables the better. I think everybody is surprised by the difference between that DD and the Sig. 10.something seems to be the widely accepted optimal length for .300 BO. Results might be different at longer ranges. At that range, doesn't look like a big deal. Fantastic video.
If you pause at 13:07 you will see why the DD penetrated less, it expanded much sooner and much more violently. Amazing performance from all of the rounds!
You mentioned twist rate kinetic energy. Well the new 8.6 blackout uses a super fast 1/3 twist rate and the kinetic energy from it at 200 yds is crazy. I have everything I need to put my 8.6 blackout together except the barrel and can't wait till those are available. I'm like you and the 300 blkout love it and heavily invested in it. My Uintah Precision 300 blkout upper has to be my favorite one to shoot (poor man's Q-Fix). Awesome video looking forward to see the results of the supersonic's.
I’m not sure what this was meant to show…the most important aspect for what you showed would be how fast the hollow point opened on impact. Depth beyond the average person is irrelevant, and this would only show the correlation between the ammo used and the kinetic energy. The effect of twist rate and barrel length would be most noticeable by the amount of dope needed at range. Please correct me if wrong and explain why?
Dude if you want to compare twist rates than do it with the same length barrel. The dd penetrated less because it was going faster and dumped its energy faster, hence the petals being peeled back so much more. This twist rate nonsense is pretty ridiculous, the only thing its doing is keeping the bullet stable, its no different for any other caliber.
That has been bugging me too, especially since going to the faster twist rate could make your 110 and 125 grain ammo inaccurate, defeating the point of having both subs and supers, subs for up close and quiet, and supers for up close and making hits out to 300 yards accurately.
This is the information I needed! Wish more companies would make 1:5 barrels in 300blk for bolt guns. Can't find one off the shelf for a Savage or Rem700 to shave my life.
There are reasons for this. Generally speaking, the slower a projectile the greater penetration (to a point) that's because higher velocities open the bullet up quicker inside the gel and the bullet typically opens bigger thus slowing it down faster.
This test needed the CMMG Dissent 300blk 6.5" barrel with 1:7 twist. I am in the market for a 300blk pdw for home defense. I was leaning on the dissent over the rattler because its lighter, cheaper, also has a more adjustable gas block, and is direct impingement. But I think the rattler just won in my book because of the faster twist rate.
Is it just me or that Bore Axe stuff doesn't leave a particularly big permanent cavity? Also, is it true that the faster 1:5 twist hurts supersonic loads because of possible overstabilization? And judging by frequency of upload here, AA are you finally returning to your normal production schedule? Wonderful!!!
You guys talked me into buying a Holosun HS510C instead of an EOTech with your torture tests. That's now long I've been watching you. I thought y'all were done with your channel because I was unsubscribed and never saw you on my feed. I'm glad this one popped up and I'm even more glad that y'all are still at it.
What an amazing video all around. You put in a ton of effort into your videos and it shows. No fluff, just jam packed with exhaustive and concise content that is so tastefully done. Even the music is great… though I still miss your original tune 😢. Thanks for for all that priceless info!
Probably one of the best gun channels out there. And your one state away from me neighbor although I still can’t put a face with who’s doing the talking.
Wish you would have tested the Sig Sauer subsonic .300 blk hunting ammo as well, since it seems like it’s more commercially available, but this is an extremely interesting video and the results are also very cool. I’m always impressed when people re evaluate the norms and use math to back up their claims. It makes it much easier to digest and understand when you have cold hard numbers to back up an idea.
Great info and detail, for such an ammo type the higher twist rate sounds agreeable in aiding the petals expansion by increasing centrifugal pressure on the bullet.
A factor you didn't address is the supersonic loads. These are subsonic, long, heavy bullets and thus the faster twist is needed to stabilize them, whereas the lighter, faster bullets do better with a slower twist rate. Rotational energy is irrelevant, it is the spin rate to stabilize that matters. Slow twisting arrows and missiles don't need much because they have guidance fins, but short projectiles can be unstable if spun too fast.
Thanks so much for this video. I always love seeing the science behind the methods/preferences regarding twist rate, bullet type, barrel length etc. Do you plan to test accuracy across the different twist rates? Also, PSA sells 1:8 twist rate 300 BLK ARs that are short barrel lengths. I'd be interested in seeing how the slower twist rates do in short barrel lengths to be a more apple to apples comparison to the faster 1:5 twist rates.
I have a PSA 8.5 inch barrel with a 1/8 twist. I am still working on what subsonic rounds it likes best. But the end cap of my suppressor tells me that fiocchi 220 grain subsonics will not work. Without the suppressor, there was no key-holing at 20 yards. However, with the suppressor, the one round I shot key-holed at 20. Initially I didn't think there was an end cap strike but upon a more detailed inspection, the round did graze the endcap. fortunately no damage. but I won't be doing it again.
Great test. I would have liked to see the difference, if any, using the same firearm and ammo without the silencer. Then add one more test using the same firearm using supersonic ammo without the silencer. thanks guys!
Personal experience with 130 hp out of a 16 inch barrel does a hella job on live tissue..... large buck didn’t take a step after shot and LOTS tissue damage!!!
Same testing has been done for years with 45-70, for a long time they couldn't figure out why in the same medium the higher velocity bullet would have less penetration, it is the energy dump on impact and that usually means earlier more violent expansion, a larger temporary wound cavity, meaning more hydrostatic shock making sure you get a good psychological stop. The DD expanded too much, that bullet was designed for lower speeds so the 10.3 inch barrel made the bullet deform much more on impact than what the designer probably wanted, crushing the pedals more. That mostly doesn't matter in hunting because you want the better penetration depth, but for defense velocity is very important, more than any miniscule energy increase from rotation. On another note, I don't know if 1/5 twist is good for lighter weight 110 and 125 grain 300blk ammo, so by going that fast you seem to be dedicating your rifle to a subsonic set up, which is fine but goes against the idea that you can easily swap between subs and supers depending on what you need, if I am running supers then I need good accuracy at least out to 200 yards, the 1/5 might ruin that capability.
Very interesting comparison. Not an issue for comparison purposes (as it was "apples to apples"), but the correct equation for Kinetic energy is 1/2*m*v**2. Thanks for the very enlightening video sir.
👆This 💯 Since we are talking about Sub-sonic 300 where can we see a video that compares the differences in Accuracy at 100 yards between 1:7 vs 1:5 Twist. By the way, your videos are great !!
Clear ballistic gel is not the FBI Standard. 10% ordnance gelatin made of Kind & Knox or Vyse 250-A at around 40°C and calibrated with a 0.177” BB fired at 590 +/-15 fps penetrating between 2.95-3.74 inches is.
I mostly just shoot it suppressed with subs unless I'm trying to clean carbon out of my can but from what I've seen I haven't had any issues with supers.
Would have been cool to have chrono'd as well. We all know barrel length makes a difference. Seeing twist chrono'd would have been cool. Either way, great vid. Thanks!
Mines a 1:7 15" barrel works fine, remember it was designed for military use and as such wasn't designed to use expanding ammo. 200-220gr match kings. It's still a .30cal hole.
You guys are one of the best creators on these topics. The attention to detail, top end video production and informative narration are just a few of the things that impress me each time I watch. Thx again, and thx for covering the 300 Blackout. Really solid info here.
i love shooting surplus. they have guns that you can't find anywhere else & their prices are usually cheaper too. i just bought an odg arex zero 1 from them for $452. thanks for the awesome review. the gel test results were surprising. i have been wanting a honey badger or rattler for a while now but i am a poor.
Wow, fresh blocks per shot? ( I haven't finished the video yet, but I dont expect it to change) I feel spoiled. You, sir, I just got a sub! Also, I love your music choices.
I don’t think the twist rates mattered here, the barrel lengths did. The DD probably pushed the bullet just a little faster, causing it to overexpand slightly and penetrate slightly less. The rattler was probably on the lower end of velocity and just couldn’t push it as deep as the Q guns. What would be interesting to see is equal length barrels with different twists.
It's great to see someone gel testing 300 subs! How does the ammo perform through denim? Does it get clogged? Regarding impact velocity, at subsonic speeds I expect you are right that faster bullets penetrate further. At roughly Mach 2, depending on bullet design, things change, and sometimes faster bullets penetrate less, because they deflect and tumble more than slower bullets. This can be seen with 77gr 5.56 bullets at 2100 fps vs 2300 fps: 2100 will pass through 32 in. of gel and exit, while 2300 will stop at about 20 in. But that's at rifle velocities. At handgun velocities, I'm not expecting rifle-type effects.
Coming back to revisit this great series because I am chasing some rabbits in the 300blk arena. I would love to see how things stacked up with all 1:5 twists or all 1:8 or 1:7 . I wonder if there is a velocity difference between the Minifix and a AR with 8 inch barrel and 1:5 twist. I know they aren't huge numbers but would be interesting to see it all compared apples to apples.
This is wonderful but if you'll get more precise calculations on rotational energy if you do the entire thing using one measurement standard. It's fine if you want to do a visual side by side comparison, but since barrel twists ratios are (unfortunately) measured in inches and inertia is measured using kilograms and meters, we're going to get some screwy numbers. It would be better to convert everything to metric and give the results in newtons instead.
Great video. Rotational vs. translational energy is only a few % until the projectile radius gets much larger (e.g. 40-mm) or the barrel twist rate is much faster...for 338 (8.6) needs to be 1 turn in 0.75 inches to equal translational energy.
The problem with calculating the rotational energy is that it comes at a loss of linear kinetic energy.... Nothing is free but maybe the projectile will slice easier who knows.
First, I want to thank you for this excellent and most informative video. I am just beginning to learn about this cartridge and some of the firearms for it. If I may I would make a suggestion/request for future videos. I would like to see the 300 blackout with bullets that may not be recommended for it such as regular soft points intended for higher velocities and perhaps cast bullets as well. Soon, we will have another situation of everything drying up and even serious shortages of every last component. So, it will be either use what you can get or nothing. Thanks again.
Great vid! "Kinetic rotational energy" is not what is making expanding subs more lethal. That ~9lb/ft of energy in the example is meaningless when contrasted with the kinetic energy transfer on target. Higher rotational speed makes the wound track larger because those petals spin and tear more in the same space, absolutely, and 1:5 twist is definitely the best way to go, but "kinetic rotational energy" is snake-oil. The rotational speed is the real MVP.
Yeah, as a mechanical engineer I’d have to agree with you. I think he wanted to calculate it in energy because that’s how fun folks usually like to measure effect on target? Idk. Energy is just the symptom of the real difference which is the speed though. I’ll also say that he should have explained that the higher twist rate slows the the bullet. This has a lot of effects but the most important 2 for this video are generally a shortened parabolic arc in longer barrel lengths, and the bullet slows enough in theory to allow complete powder burn in shorter barrel lengths.
I have some comments. Just attempting to be constructive. There are a couple of conclusions you came to that could be explained as right result, wrong reason. Keep in mind we're talking about hollow point or expanding bullets. This changes if you move to non-expanding bullets. The energy it takes to expand the petals is dissipated in the gel block. Faster bullets will have a more energetic expansion. That expansion will actually slow the bullet in media faster than a less energetic expansion during energy transfer. End result is that faster hollow points tend to penetrate less than slower hollow points all other things being equal. A hollow point can behave like an FMJ at the right speed and way over penetrate. It seems counter intuitive, but it's the energy transfer. So the shorter barrel, faster twist isn't penetrating deep because of twist. It's because the expansion has less energy transfer. Regarding rotational energy. First, we have to understand that it will impart rotational torque on the target, not linear force in the direction of travel. IE, it's going to twist the target, not push the bullet deeper. Also, keep in mind that gains you are seeing in rotational energy are actually insignificant in comparison to the linear kinetic energy. A 220gr bullet traveling 1000 fps has a calculated energy of 488 ft-lb. The difference between your 1:8 calc and 1:5 calc is a 1.1% increase of the total energy. An increase of 3" of depth is a 15% increase in penetration. That's not possible based on adding only 1.1% more energy. It might explain the 20" vs 20.25", but that could also fall within margin of error. Finally, twist rate is an aerodynamically stabilizing function. You cannot just buy the fastest twist barrel and be done. Twist rate is tied to length of the projectile. A longer projectile requires a faster twist rate to spin stabilize. If you shoot a shorter projectile in that same twist, you may over spin the bullet cause significant accuracy reduction. Bullet length is a result of weight, so its often said the heavier bullet the faster the twist, but it's really about projectile length. It's possible that the 195gr bullet is not being spin stabilized by the 1:8 twist traveling at less than 1000fps. BUT, if you loaded a 115gr bullet in that 1:5 it could make things worse for accuracy. I've accidentally overspun bullets to the point they fragmented in flight. Check your paper targets at 35 yds and see if the bullet holes are oblong or oval. That would indicate an unstable projectile. This is not to brag, just to explain my comments above. My background is in Physics/engineering. So I tend to dig way deeper into this kind of thing than people who aren't obsessed by irrelevant technical details... LOL. Nicely done video.
Good info in this video. Thanks for making it. I think it would be interesting to compare barrel twist rate to the rate of spin that the bullet exhibits in gel. Watching this vid it appears that the 1:5 barrels actually spun the bullets around 1:8 to 1:10. Just a thought. Another interesting comparison would be plain ballistics gel as opposed to gel with some bones in them. This should show some interesting things for terminal ballistics. Happy shooting!!!
A friend of mine got a job with a small suppressor company and is starting his firearms journey. I shared this video with him because we’re all learning together.
LOL Thanks man! Appreciate you watching!
Good for him! I have a Cerakote shop in my garage and I'm a collision painter by trade. I consistently went to three local gun stores to get a job and get out of the Body Shop rat race and I couldn't get a job with no one. I brought 3 examples of my work along with my firearm knowledge..........nope. Apparently God was telling me some.
@@tangomantacticalhow’s it going with the cerekote buisness my fellow body shop brutha?
@@JohnnyBravo02 its been adventurous. Its not like spraying PPG. The flash and bake times are weird. I'm still learning. I am getting better though. Have a blessed weekend brother.
@@tangomantactical glad to hear you’re improving! You know how it goes, it’s all about repetition and consistency . You have a blessed weekend as well bro
You’re missing a big variable here. As a rule of thumb, when velocity doubles, the density of the substance essentially quadruples in relationship to the projectile. Think about jumping into water from five feet vs fifteen feet. Thus, when the faster bullet hits the medium, it is met with greater resistance than a slower projectile, which affects penetration. Which affects the temporary and permanent would cavity and also affects incapacitation of an animal or human (think blood pressure changes and nervous system shock, etc.)
Good point..
I am absolutely mesmerized by your intense detail with all of your videos!!! And have to say your voice should be on National Geographic!! Your detail to attention is unsurpassed to all other videos. Thank you for what you do! Please keep the amazing content coming!!
Lol thanks! I always try to make the video I would want to see on whatever topic. I don’t get them all right, but I try. Thanks for watching!
Ya, unique voice.
When I’m seriously looking for a specific item’s review, it’s AA for a one and done. Simply thorough with no nonsense.
He is basically the most thorough tester of precision equipment. Yes his media quality is top notch. Few are close to this level.
1:5 or die. That rattler impressed me. With the short barrel I’m shocked it performed that well. Even with the twist rate I didn’t think the velocity would be enough to get the projectile to expand that much.
Yeah I agree the Rattler was the big surprise and eye opener of the bunch. I’m definitely gaining a lot more faith in that firearm. Thanks for watching.
@@AlabamaArsenal one thing I have seen in other gel test it is possible that the mini fix expanded faster which would cause it to slow down quicker and stop shorter than the honey Badger the velocity would be similar but just that extra inch in powder burn could cause that to happen
Barnes 110g TAC-TX will expand down to 1300 fps
@@AndyAdventuring My favorite bullets along with the TTSX loaded by Black Hills.
@@AlabamaArsenalIt's interesting that the Honey Badger penetrated so much more than the Rattler. They have the same twist rate and the HB barrel is only .5" longer. That's a big difference for half an inch!
I’m more interested in how the twist rate affects the rifles accuracy more than the minuscule amount of energy increase it delivers. If the group size cuts in half.. say, 3 MOA to 1.5 MOA, then the higher twist rate means something to me. If it does indeed stabilize heavier bullets to the point accuracy is much improved, it’s a winner.
Supposedly twist rate and accuracy isn't a clear cut thing. For example perfectly stabilizing bullets only works for a specific range as the spin slows over distance. Usually testing is only done at 100 yards so all data around stability is only for this range. When you get out to long range such as 800 yards or further, the bullet is generally unstable and this can cause wild shots when it punches into the transonic speeds. In contrast fast twists that overstabilize bullets may cause wider groups at close range, but because the bullet slows down the spin at longer ranges and still has more spin than a conventionally stabilized bullet, the groups at long range are actually tighter.
My degree is in Biology, not physics, trauma surgery, or ballistics; so I am far from an expert. Evaluate my opinion accordingly. My main takeaway so far is that the 1:8 twist rate appeared to have created a larger temporary and permanent wound cavity. This is what I think I want as it demonstrates a greater energy dump in that first 14 inches. That is where I want the damage on a soft target, yes? The greater angular momentum caused by the higher twist rate seems to be going towards more penetration. The round is conserving more energy that is going towards deeper penetration, dumping that energy over a longer path, amount of time during that longer path, and dumping more of that energy out of that target "ideal wound" area.
What I would love to see is a comparison from identical, or near identical, barrel lengths with the only significant difference being the twist rate. A longer barrel may mean a slightly higher velocity, and a higher twist rate may contribute to greater accuracy over distance (?), but I would love to see something closer to an apple to apple to help with this specific debate.
Thanks for your dedication to content quality. Would love to see Barnes TTSX 110g gel test data, or similar. Love this channel. 🇺🇸
Appreciate that! Maybe next time. Thanks for watching!
It’s the BEST super. end of story, their 120gr is next. All I buy is the 110 Barnes and Hornady TAP 110.
Id like to see the Barnes 110 as well.
I agree!
The longer barrel actually caused more expansion. Although it has a smaller diameter in the end because of the bullet design it hit the same expansion and then peeled back further. In my opinion the extra speed caused more energy dump resulting in less penetration. Less speed more fmj like penetration.
Majority of subsonic loadings are designed for 16" barrels, the shorter ones will be slower, regardless of negligible loses in velocity there is a loss in velocity. I wouldn't go under 15" but you guys have silly nfa hoops to jump through to avoid SBRing things. The perfect 300blk is a 15" carry handle uppered rifle, gives you two sets of sights and 2 zeros.
Jason, I agree that he wasn’t looking at the right things. The distance from the front of the gel to the expansion is more telling than the depth into the gel.
thats the way Sig made it. 5.5" barrel for 223 and, 5.5" barrel for 300bo. i agree with what your saying but, again Sig designed it. they do not make garbage. i shot 20rds threw it and it shot like a dream. i definitely would not want to get hit by it, regardless if it doesn't expand or the velocity is way off. this firearm was strictly designed as a back pack, vehicle, by your night stand. thanks for watching the video. Subscribe! i have more content coming this weekend. God bless.
@@ancientrenegade9243 got any proof?
Been saying this for years, the final measured expansion is not always the maximum expansion. Both are valuable data points but need to be defined separately.
My favourite caliber. Thanks for this series.
Can't wait for the supersonic testing video. I love my rattler, and since I don't have a chronograph yet I'm very curious to see the velocity with supers from that barrel.
Your minimalist audio presentation is the most impressive part of this video. Thanks ~
That ballistic gel is awesome! So clear, you can really see the details
Alabama Arsenal’s videos are not only informative but they are so Zen to watch!…best background music, video editing and narration on the interwebs 🤘🤘🤘😎😎😎
I’ve enjoyed watching your channel since the beginning and how you guys breakdown and diagnose how it works in layman terms for a simple folks,
I wish UA-cam scrubs had a four or five star rating because y’all deserve at least a 10 on every level, thanks for sharing your knowledge, 🙏
Great video. Thanks. I have also tested numerous 30cal subsonic rounds. As most available 300blk rounds don't expand subsonic I have a found a slower twist rate to create a much greater permanent wound cavity. There are very few expanding 30cal subsonic bullets available outside USA. I have found "minimal stabilization" performs much better in 30 subsonic with non expanding bullets. Even the Hornady 30 cal subsonic perform really poorly. I have found a 9 to 9.5 twist with over 200gn bullets to be ideal. They turn sideways immediately upon impact and cut a 1 inch plus wound channel nearly all the way through most medium game. I am certain the permanent wound cavity will be greater than what you showed in this video. Even the cheap Lee 230gr cast bullet will kill a lot better than any over stabilized jacketed bullet in 30 cal. I run the Lee 230 in a 9.5 twist and I doubt you will beat it's permanent wound cavity with expanding bullets. Cheers and take care.
Don’t you want a clean shot with hunting? Sloppy aim.
@@WilliamHClarkiii what are you talking about? Where did I say anything about sloppy aim or not taking a clean shot. I'm tipping you don't have a clue about what I'm talking about. Brush up on some ballistic principles maybe.
@@neckstumping I’m saying as a hunter don’t you want a clean shot through the animal
I would love to see the DDM4 PDW with the 7” 1:7 twist barrel added to this mix. I do think that a 1:8 twist rate is probably too slow for subsonic 300 BLK. I personally opted for one over a Sig rattler. As always, I appreciate your time, effort and expense in making these informative videos.
This video was so good that I doubt a second one with this caliber would ever happen but that’s what I own and I couldn’t agree more.
after initially looking at Q Honey Badger and Noveske Ghetto Blaster
I turned my attention to Sig Rattler and DDpdw
went with the DDpdw as well
@@brighthought11 Thank makes me feel even better about my choice
I went with the DDpdw as well. Not a fan of how big the rails on the sig are. They just look uncomfortable. Also not a fan of folding stocks. Went with the sbr version ✊️✊️
Glad to see fresh blocks for each round. This guy gets it!
I’d love to see this test done with super sonic and perhaps throw in a 12.5” 1:7 twist
I love my 10.5" barrel. With Black Hills 110 gr ammo using Barnes TTSX the velocity is around 2250 fps. This makes it a point and shoot gun out to about 300 yards. The energy is roughly equivalent to an AK with a 16" barrel. For such a small package it performs great as my home defense and truck gun.
One of the other guys mentioned V x density.. but I would like to point out.. a friend of mine, knows little about firearms and he wanted a.308 with a 22” barrel.. I recommend to him having a longer barrel would cause more drag on the projectile and would counter the pressure you’re trying to build. In other words there has to be a balance between twist and length in relation to the caliber being used..
Excellent video. Minor point (or maybe not), it would have been helpful to have seen chronograph numbers on these rounds. A good number of 300 AAC shooters are handloaders and velocity info is extremely important in comparing projectiles and barrel lengths.
Truly excellent video, one of the first YT vids I really feel I should pay for. I have a wide selection of 300BLK barrels, from 1:5 to 1:8 and 4.75" to 10"
A few thoughts...
1. I've seen accuracy improvements that came with a faster twist barrel. Now it's not scientific, might be a better barrel in general, a better build etc. But it is the trend I've seen.
2. I'm VERY curious to see the effects of faster twist on fracturing bullets in gel. As far as I'm aware nobody is commercially loading the 198gr Lehigh and there's no other fracturing subsonic. But the 115gr, and 100gr offerings from Gorilla I'm very curious about. I'd expect the faster twist to so a lot with a fracturing bullet compared to an expanding bullet.
3. That then brings up, what is too fast for such a bullet? Put that 100gr Gorilla fracturing into a 1:5, will it explode, no idea haven't tried it yet. Might soon though, I have the pieces to try, just haven't put one in the other yet.
I don't think the claim being touted is that high twist increases penetration, as much as it increases terminal effect via expansion at a lower threshold. Increased expansion at lower velocity can mean LESS penetration, because energy dump is via drag/surface area interaction by velocity. If there's a speed limit on your bullet (subsonic) you can get more energy terminally at a given depth by increased spin (if the bullet expands) the petals make more rotations in a given distance inside the target, that's more total intervals surface area contacted/cut/crushed. But increased drag lowers overall penetration. It just so happens though that sinsonics don't have penetration problems, they have energy dump problems. They tend to not expand, and then ice pick, tumble once, icepick again, and then end up in New Jersey somewhere.
The twist is supposed to translate that wasted energy into better expansion and initial terminal effect. But only as a side effect of the primary purpose: increased accuracy of extra long bullets at very low velocity.
From watching Johnny's Reloading Bench you can see how much he struggled to get good subsonic accuracy when reloading, especially the larger bullets.
*edit* there's another relevant effect of high twist in a super short 300 blk: supersonic effectiveness. As many tests on The Chopping Block have shown, lots of 300 blk loads don't expand properly in shorter barrels. They can approach or drop below the 1800 fps that 99% of .308 bullets are designed to expand at as a minimum performance threshold. Many will expand, but minimally compared with a similar design in a slightly longer barrel.
But, especially with copper bullets, the twist seems to aid in the petals opening a bit more even as the bullet approaches that bleeding edge of nor expanding otherwise.
MAC showed that his rattler gets fantastic performance from a 110 gr supersonic.
Love these videos! Content, information, filming, music, commentary, b-real, etc. are all perfect. I truly enjoy the Silencer School series. From someone who watches a lot of firearms videos from any and all channels, BRAVO 👏. 10 outta 10 would recommend!
Would've been great to test 1:7 twist 6/7.5 inch barrel as well, didn't even see you mention that twist rate... I know it's a DD, but 1:8 twist are normally the cheapest of 300 blk barrels. Great video!
Awesome video and testing ! Man sure wish I would’ve seen this video before hand, I just purchased a 6” barrel 300 blackout with 1:8 twist. I’ve been seeing more and more videos on that sig rattler and I’m impressed more every time, that thing is packing a punch for that short barrel with 1:5 twist rate, very effective and don’t be fooled it will reach out there and make 200 yard shots very accurately as was shown in military arms channel video. Prolly would’ve went with the sig over the 6” aero precision 300 I just bought if seen these test sooner. I’ll definitely be on the hunt for a 1:5 twist barrel for my gun as I do believe they make a huge difference especially in sub sonic. But thanks again for the awesome video
Super appreciate ya'll doing this test! Adds more evidence toward confirming what a lot of what the community believes in terms of maximizing the effectiveness of 300BLK and the types of results you can get from the cartridge. Very cool.
Man, this is exactly what I was looking for. I have the 1/5 300 blk rattler and also some 1/7 300 barrels. Good to know this info.
On twist rates. Spinning faster than required for stability is not required……..same as for tops. Bullets and tops are either stable or they are not. Spinning them too fast can tear their jackets apart and bullets spinning faster provide no real advantage in external ballistics. Also, Heavier bullets are necessarily longer. The longer the bullet, the faster you need to spin it to stabilize it in flight. It’s the bullet length that matters. Spin rate is determined by barrel twist and bullet velocity in the barrel. A short barreled rifle needs a higher twist rate as it generally produces less muzzle velocity. Heavy for caliber bullets (I.e. long bullets) need faster twist rates too. I’m not convinced that twist rates produce much evidence in terminal ballistics other than a marginally stable bullet will produce more damage as it tumbles after impact. Bullets damage by expansion and/ or fragmentation and also by velocity in the form of hydrostatic shock.
You've disproved your own argument, 300BLK subs are very long, in short barrels, at slow speeds. It's not really possible to over spin a 300BLK sub. The ONLY possible downside is maybe blowing up some fragile light supersonic bullet.
The twist also clearly provided some terminal ballistic performance.
Perfect discourse on twist rates sir
@@snek9353 The point that you missed is that the twist rate is to be used to produce the required rpm to stabilize the projectile…..not for any very small or imagined terminal effect. Long bullets and/ or lower velocities require a faster twist rate to produce the required rpm. Spinning it faster than the minimum required is a waste. So, yes, short barrel subs require faster twist rates…..for stabilization.
@@747driver3 A waste of what? There's no downside to a fast twist with subs. There's clearly some terminal effect with no downside.
@@snek9353 I disagree with your assessment of the terminal effect. Nothing I have seen clearly demonstrates this. Overspinning is stressful on the bullet. Any deformation affects in flight.
Looks like a really well developed round. The cavity it leaves behind is nasty.
Gel tests are always great to see. The more variables the better.
I think everybody is surprised by the difference between that DD and the Sig.
10.something seems to be the widely accepted optimal length for .300 BO.
Results might be different at longer ranges. At that range, doesn't look like a big deal.
Fantastic video.
If you pause at 13:07 you will see why the DD penetrated less, it expanded much sooner and much more violently. Amazing performance from all of the rounds!
DD is trash with slow twist
You mentioned twist rate kinetic energy. Well the new 8.6 blackout uses a super fast 1/3 twist rate and the kinetic energy from it at 200 yds is crazy. I have everything I need to put my 8.6 blackout together except the barrel and can't wait till those are available. I'm like you and the 300 blkout love it and heavily invested in it. My Uintah Precision 300 blkout upper has to be my favorite one to shoot (poor man's Q-Fix). Awesome video looking forward to see the results of the supersonic's.
I’m not sure what this was meant to show…the most important aspect for what you showed would be how fast the hollow point opened on impact. Depth beyond the average person is irrelevant, and this would only show the correlation between the ammo used and the kinetic energy. The effect of twist rate and barrel length would be most noticeable by the amount of dope needed at range. Please correct me if wrong and explain why?
Thank you for what you do, been following the series & channel slowly gathering info for the next 300 build.!!!!
Dude if you want to compare twist rates than do it with the same length barrel. The dd penetrated less because it was going faster and dumped its energy faster, hence the petals being peeled back so much more. This twist rate nonsense is pretty ridiculous, the only thing its doing is keeping the bullet stable, its no different for any other caliber.
He has what he has, I'm sure if he had examples of the same length and different twist he'd have used them.
That has been bugging me too, especially since going to the faster twist rate could make your 110 and 125 grain ammo inaccurate, defeating the point of having both subs and supers, subs for up close and quiet, and supers for up close and making hits out to 300 yards accurately.
Sectional density is giving it an extra 6" or so, but this is basically the equivalent of a .45acp HST.
Now do the same thing with supersonic 300blk, PLEASE I have a feeling barrel length & twist rate will have far more impact on supers
This is the information I needed! Wish more companies would make 1:5 barrels in 300blk for bolt guns. Can't find one off the shelf for a Savage or Rem700 to shave my life.
Can't wait to see the supers. Use a 16" barrel as a control for that please. My HD is a 16" 300 Blk running sups.
There are reasons for this. Generally speaking, the slower a projectile the greater penetration (to a point) that's because higher velocities open the bullet up quicker inside the gel and the bullet typically opens bigger thus slowing it down faster.
This test needed the CMMG Dissent 300blk 6.5" barrel with 1:7 twist. I am in the market for a 300blk pdw for home defense. I was leaning on the dissent over the rattler because its lighter, cheaper, also has a more adjustable gas block, and is direct impingement. But I think the rattler just won in my book because of the faster twist rate.
Just found this channel. Amazing production quality. Subbed
*ALABAMA ARSENAL IS SO HAWT RIGHT NOW*
It sounds like a paintball gun. That's awesome.
35yds shots on Clear Ballistics 10% gel (FBI standard), ammo: Callaway Ballistics Bore Axe 195gr subsonic MKZ
4:51 DDM4 300S, 10.3'', 1:8
**All guns after that have a 1:5 twist**
6:41 Q Mini Fix, 8''
8:19 Q Honey Badger, 7''
10:10 Sig MCX Rattler, 5.5''
Is it just me or that Bore Axe stuff doesn't leave a particularly big permanent cavity?
Also, is it true that the faster 1:5 twist hurts supersonic loads because of possible overstabilization?
And judging by frequency of upload here, AA are you finally returning to your normal production schedule? Wonderful!!!
Thanks
I wanted to see this type of video for a long time. Thank you.
Should have tried DDM4 PDW's 7 inch with 1/7 twist, that would give you intermediary data between 1/8 and 1/5.
Now hoping that you guys can get your hands in 8.6 Blackout.
That 1 in 3 should be insane.
You guys talked me into buying a Holosun HS510C instead of an EOTech with your torture tests. That's now long I've been watching you. I thought y'all were done with your channel because I was unsubscribed and never saw you on my feed. I'm glad this one popped up and I'm even more glad that y'all are still at it.
What an amazing video all around. You put in a ton of effort into your videos and it shows. No fluff, just jam packed with exhaustive and concise content that is so tastefully done. Even the music is great… though I still miss your original tune 😢. Thanks for for all that priceless info!
As always, an excellent video!!! 🔥
Appreciate you watching man!
thank you so much for using new gel blocks for each round!!!!!!!!!!!! it's done often enough, understandably
Probably one of the best gun channels out there. And your one state away from me neighbor although I still can’t put a face with who’s doing the talking.
Wish you would have tested the Sig Sauer subsonic .300 blk hunting ammo as well, since it seems like it’s more commercially available, but this is an extremely interesting video and the results are also very cool. I’m always impressed when people re evaluate the norms and use math to back up their claims. It makes it much easier to digest and understand when you have cold hard numbers to back up an idea.
Great info and detail, for such an ammo type the higher twist rate sounds agreeable in aiding the petals expansion by increasing centrifugal pressure on the bullet.
A factor you didn't address is the supersonic loads. These are subsonic, long, heavy bullets and thus the faster twist is needed to stabilize them, whereas the lighter, faster bullets do better with a slower twist rate. Rotational energy is irrelevant, it is the spin rate to stabilize that matters. Slow twisting arrows and missiles don't need much because they have guidance fins, but short projectiles can be unstable if spun too fast.
Glorious!
God bless, gentlemen!
God bless you as well! And appreciate you watching!
I like how the smoke puffs out from the middle of the blocks
Thanks so much for this video. I always love seeing the science behind the methods/preferences regarding twist rate, bullet type, barrel length etc. Do you plan to test accuracy across the different twist rates? Also, PSA sells 1:8 twist rate 300 BLK ARs that are short barrel lengths. I'd be interested in seeing how the slower twist rates do in short barrel lengths to be a more apple to apples comparison to the faster 1:5 twist rates.
I have a PSA 8.5 inch barrel with a 1/8 twist. I am still working on what subsonic rounds it likes best. But the end cap of my suppressor tells me that fiocchi 220 grain subsonics will not work. Without the suppressor, there was no key-holing at 20 yards. However, with the suppressor, the one round I shot key-holed at 20. Initially I didn't think there was an end cap strike but upon a more detailed inspection, the round did graze the endcap. fortunately no damage. but I won't be doing it again.
Great test. I would have liked to see the difference, if any, using the same firearm and ammo without the silencer. Then add one more test using the same firearm using supersonic ammo without the silencer. thanks guys!
Personal experience with 130 hp out of a 16 inch barrel does a hella job on live tissue..... large buck didn’t take a step after shot and LOTS tissue damage!!!
“That explains a couple 7.5 inch 5.56 I have” ahahaha I wholeheartedly feel that. Thankfully I now know about 300 blackout for CQC urban environments
This was a GREAT demonstration! 🎉
Glad you liked it! Thanks for watching!
This is what I've been looking for for at least a year! Great content!
Same testing has been done for years with 45-70, for a long time they couldn't figure out why in the same medium the higher velocity bullet would have less penetration, it is the energy dump on impact and that usually means earlier more violent expansion, a larger temporary wound cavity, meaning more hydrostatic shock making sure you get a good psychological stop. The DD expanded too much, that bullet was designed for lower speeds so the 10.3 inch barrel made the bullet deform much more on impact than what the designer probably wanted, crushing the pedals more.
That mostly doesn't matter in hunting because you want the better penetration depth, but for defense velocity is very important, more than any miniscule energy increase from rotation.
On another note, I don't know if 1/5 twist is good for lighter weight 110 and 125 grain 300blk ammo, so by going that fast you seem to be dedicating your rifle to a subsonic set up, which is fine but goes against the idea that you can easily swap between subs and supers depending on what you need, if I am running supers then I need good accuracy at least out to 200 yards, the 1/5 might ruin that capability.
Love the artisitc style and the educational benifit.
Tolerance and Education through Understanding.
Well Done!
Very interesting comparison. Not an issue for comparison purposes (as it was "apples to apples"), but the correct equation for Kinetic energy is 1/2*m*v**2. Thanks for the very enlightening video sir.
Great video. However the twist rate is more relating to accuracy at “distance”. Would be good to have put that in.
👆This 💯 Since we are talking about Sub-sonic 300 where can we see a video that compares the differences in Accuracy at 100 yards between 1:7 vs 1:5 Twist.
By the way, your videos are great !!
Love it!!!!! Wasn't that long at all . These comparison video have become my favorite.
What an impressive channel you've built. A great asset to us gunners. Thank you for your hard work Alabama Arsenal
Alabama Arsenal out here doing the lords work. Thank you for doing this test!
Another great video in the bag! Well done!
Appreciate you watching man!
Awesome content, as always gentlemen. Your channel is what I hope mine becomes when it grows up. Your collection of guns is awe-inspiring.
I wish I had seen this video and you other videos on 300 blackout before I bought my PSA 7 in 1/7 upper. I still love it though.
Interesting
Great job guys I really appreciate the content and financial obligation y'all put forth to make the top notch content
Thank you man, and appreciate you watching!
Clear ballistic gel is not the FBI Standard. 10% ordnance gelatin made of Kind & Knox or Vyse 250-A at around 40°C and calibrated with a 0.177” BB fired at 590 +/-15 fps penetrating between 2.95-3.74 inches is.
Awesome video and comparison! My MCX Virtus SBR has a 9" - 1:5 twist barrel, my first dive into the 300 blackout realm. Absolutely love the thing.
I didn't know they made a 1:5 that long, any issues with fast bullets coming apart?
I mostly just shoot it suppressed with subs unless I'm trying to clean carbon out of my can but from what I've seen I haven't had any issues with supers.
Great video. Thank you for the detailed content!
Thank you for watching man!
Would have been cool to have chrono'd as well. We all know barrel length makes a difference. Seeing twist chrono'd would have been cool. Either way, great vid. Thanks!
Mines a 1:7 15" barrel works fine, remember it was designed for military use and as such wasn't designed to use expanding ammo. 200-220gr match kings. It's still a .30cal hole.
You guys are one of the best creators on these topics. The attention to detail, top end video production and informative narration are just a few of the things that impress me each time I watch. Thx again, and thx for covering the 300 Blackout. Really solid info here.
I feel like a 8.5" barrel with a 1/7 twist is fairly common too.
I appreciate the spinning top analogy.
Excellent video as always
Really appreciate you taking the time to watch. Very excited about 8.6BLK. Hoping I can get my hands on it.
i love shooting surplus. they have guns that you can't find anywhere else & their prices are usually cheaper too. i just bought an odg arex zero 1 from them for $452. thanks for the awesome review. the gel test results were surprising. i have been wanting a honey badger or rattler for a while now but i am a poor.
Wow, fresh blocks per shot? ( I haven't finished the video yet, but I dont expect it to change) I feel spoiled. You, sir, I just got a sub!
Also, I love your music choices.
I don’t think the twist rates mattered here, the barrel lengths did. The DD probably pushed the bullet just a little faster, causing it to overexpand slightly and penetrate slightly less. The rattler was probably on the lower end of velocity and just couldn’t push it as deep as the Q guns. What would be interesting to see is equal length barrels with different twists.
It's great to see someone gel testing 300 subs! How does the ammo perform through denim? Does it get clogged?
Regarding impact velocity, at subsonic speeds I expect you are right that faster bullets penetrate further. At roughly Mach 2, depending on bullet design, things change, and sometimes faster bullets penetrate less, because they deflect and tumble more than slower bullets. This can be seen with 77gr 5.56 bullets at 2100 fps vs 2300 fps: 2100 will pass through 32 in. of gel and exit, while 2300 will stop at about 20 in. But that's at rifle velocities. At handgun velocities, I'm not expecting rifle-type effects.
Coming back to revisit this great series because I am chasing some rabbits in the 300blk arena. I would love to see how things stacked up with all 1:5 twists or all 1:8 or 1:7 . I wonder if there is a velocity difference between the Minifix and a AR with 8 inch barrel and 1:5 twist. I know they aren't huge numbers but would be interesting to see it all compared apples to apples.
This is wonderful but if you'll get more precise calculations on rotational energy if you do the entire thing using one measurement standard. It's fine if you want to do a visual side by side comparison, but since barrel twists ratios are (unfortunately) measured in inches and inertia is measured using kilograms and meters, we're going to get some screwy numbers. It would be better to convert everything to metric and give the results in newtons instead.
This is something I've wanted to see for a long time. Thanks!
Great video. Rotational vs. translational energy is only a few % until the projectile radius gets much larger (e.g. 40-mm) or the barrel twist rate is much faster...for 338 (8.6) needs to be 1 turn in 0.75 inches to equal translational energy.
Awesome test. Let's see a 10 inch 1:7 next. 🙂
Nice to have Informative Presented in such a good format, thanks For the effort
The problem with calculating the rotational energy is that it comes at a loss of linear kinetic energy.... Nothing is free but maybe the projectile will slice easier who knows.
First, I want to thank you for this excellent and most informative video. I am just beginning to learn about this cartridge and some of the firearms for it. If I may I would make a suggestion/request for future videos. I would like to see the 300 blackout with bullets that may not be recommended for it such as regular soft points intended for higher velocities and perhaps cast bullets as well. Soon, we will have another situation of everything drying up and even serious shortages of every last component. So, it will be either use what you can get or nothing. Thanks again.
Great vid!
"Kinetic rotational energy" is not what is making expanding subs more lethal. That ~9lb/ft of energy in the example is meaningless when contrasted with the kinetic energy transfer on target. Higher rotational speed makes the wound track larger because those petals spin and tear more in the same space, absolutely, and 1:5 twist is definitely the best way to go, but "kinetic rotational energy" is snake-oil. The rotational speed is the real MVP.
This is correct ^
I have a bachelors in math and I’ve spoken to two friends with engineering degrees about this and we all agree with you, Thomas.
Yeah, as a mechanical engineer I’d have to agree with you. I think he wanted to calculate it in energy because that’s how fun folks usually like to measure effect on target? Idk. Energy is just the symptom of the real difference which is the speed though.
I’ll also say that he should have explained that the higher twist rate slows the the bullet. This has a lot of effects but the most important 2 for this video are generally a shortened parabolic arc in longer barrel lengths, and the bullet slows enough in theory to allow complete powder burn in shorter barrel lengths.
Thank you. Can you do another video with a 16” barrel and SuperSonics?
I have some comments. Just attempting to be constructive. There are a couple of conclusions you came to that could be explained as right result, wrong reason. Keep in mind we're talking about hollow point or expanding bullets. This changes if you move to non-expanding bullets. The energy it takes to expand the petals is dissipated in the gel block. Faster bullets will have a more energetic expansion. That expansion will actually slow the bullet in media faster than a less energetic expansion during energy transfer. End result is that faster hollow points tend to penetrate less than slower hollow points all other things being equal. A hollow point can behave like an FMJ at the right speed and way over penetrate. It seems counter intuitive, but it's the energy transfer. So the shorter barrel, faster twist isn't penetrating deep because of twist. It's because the expansion has less energy transfer.
Regarding rotational energy. First, we have to understand that it will impart rotational torque on the target, not linear force in the direction of travel. IE, it's going to twist the target, not push the bullet deeper. Also, keep in mind that gains you are seeing in rotational energy are actually insignificant in comparison to the linear kinetic energy. A 220gr bullet traveling 1000 fps has a calculated energy of 488 ft-lb. The difference between your 1:8 calc and 1:5 calc is a 1.1% increase of the total energy. An increase of 3" of depth is a 15% increase in penetration. That's not possible based on adding only 1.1% more energy. It might explain the 20" vs 20.25", but that could also fall within margin of error.
Finally, twist rate is an aerodynamically stabilizing function. You cannot just buy the fastest twist barrel and be done. Twist rate is tied to length of the projectile. A longer projectile requires a faster twist rate to spin stabilize. If you shoot a shorter projectile in that same twist, you may over spin the bullet cause significant accuracy reduction. Bullet length is a result of weight, so its often said the heavier bullet the faster the twist, but it's really about projectile length. It's possible that the 195gr bullet is not being spin stabilized by the 1:8 twist traveling at less than 1000fps. BUT, if you loaded a 115gr bullet in that 1:5 it could make things worse for accuracy. I've accidentally overspun bullets to the point they fragmented in flight. Check your paper targets at 35 yds and see if the bullet holes are oblong or oval. That would indicate an unstable projectile.
This is not to brag, just to explain my comments above. My background is in Physics/engineering. So I tend to dig way deeper into this kind of thing than people who aren't obsessed by irrelevant technical details... LOL. Nicely done video.
Good info in this video. Thanks for making it.
I think it would be interesting to compare barrel twist rate to the rate of spin that the bullet exhibits in gel. Watching this vid it appears that the 1:5 barrels actually spun the bullets around 1:8 to 1:10. Just a thought.
Another interesting comparison would be plain ballistics gel as opposed to gel with some bones in them. This should show some interesting things for terminal ballistics.
Happy shooting!!!