Faxon Q&A #2: Barrel profiles, length, fluting and more!
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- Опубліковано 29 сер 2024
- Session 2 with Nathanial from Faxon! This time we delve into barrel profiles, barrel lengths, fluting and finalize some thoughts on nitride.
If you're interested in learning what really is going on with rifle barrels, then this is the video for you!
0:48
General discussion.
4:00
Original M16 barrel vs HBAR.
Changing bullet impact with sling pressure.
5:37
Building/buying first AR. What barrel profile do you want?
8:43
The military’s needs in a barrel profile and a civilian’s aren’t necessarily the same.
11:24
Why are people putting M4 profile barrels on semi-auto guns?
13:09
Ideally barrels are tapered, fat at the receiver and thin at the muzzle.
Barrel “whip”.
Where’s the hottest part of a barrel?
15:06
Discussion about fluting of barrels
17:04
Fluted barrels and full auto guns?
17:50
IV8888’s melt down video with Faxon barrel.
18:45
Government profile barrels are the worst of both worlds?
20:20
InRange’s visit with Jim Sullivan and his efforts towards enhancing the sustained fire capabilities of the M16 weapon system. Superheated gas tubes and failures.
21:30
Discussion about barrel lengths.
Barrel length does not determine accuracy.
So why pick specific barrel lengths?
Shorter barrels actually have more accuracy potential.
You want the shortest barrel possible for your specific application.
22:45
Small bore/high velocity cartridges are sensitive to barrel length.
Barrel length for optimal powder burn and prevention of being overbore.
Barrel length, and thus velocity, determines ballistic capabilities at range.
25:15
Why do larger diameter cartridges give up less velocity with shorter barrels than small diameter alternatives?
Surface area of the projectile factors into the pressure generated during the firing process.
Pressure increases with smaller diameter but higher velocity cartridges.
26:55
You want to ensure that your bullet stays supersonic until it reaches the target.
What happens when your bullet’s velocity falls below supersonic in flight?
28:26
Follow up on questions about nitride and potential nitride concerns.
Krieger Barrel’s email about nitride.
The nitride processing is done by a 3rd party, not the barrel manufacturer. Warranty concerns.
Nitriding a poorly manufactured barrel means you actually could make it worse.
The nitride process, temperature and what can go wrong if done improperly.
When done properly, multiple manufacturers agreed that it is a good solution.
QC on barrels post nitride process.
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Thanks for having Faxon on for another episode. We truly enjoy speaking on barrels and making them!
Thank you for being willing to spend your time doing this with us! ~Karl
Faxon Firearms I have been on the fence about buying one of your barrels. But it seems that faxon really knows what there doing and you have won my business.
We're honored!
Thanks again for the interesting insights you gave us!
That's a good one. Will be happy to address.
This is so great. The guy from Faxon is like a college professor lecturing on barrel dynamics. I found this a very interesting discussion and learned alot. Nice work.
Good Karl, only a sith deals in absolutes
+PeopleFromYourSchool Apparently I am not a sith. :) ~Karl
PeopleFromYourSchool
prequel memes are leaking everywhere
These interviews are so interesting and i hope we keep seeing more. Because this gives us so much insight into the industry and the development of firearms.
I frickin' love this series; this guy is a genius when it comes to barrels. I know where I'll be going when it comes to get a barrel for my 308 build.
You should speak with Bob Faxon. He's the real brains with 30 more years of experience than I have. -Nathan
How did the build go
You mentioned "the design of cartridges is a whole 'nother conversation."
You should have that conversation on another video.
I agree. Cartridge manufacturers seem to develop and load for maximum velocity from test barrels (24 or 26”) - instead of developing and loading for intended end use barrel length.
@@likydsplit8483 And too often they do not want to specify their test length or acknowledge the most preferred end user length. But this is a wonderful Q&A.
yes
This series is very educational and I hope to see more!! There's so much crap on the internet it's nice to get solid information from an expert.
For being the technical gun nerd that I am, all this information is so cool to hear! Being someone who actually wanted to buy an m4 profile barrel i didn't even think about the actual torque put on the barrel from the extra weight on the front! Thank you InrangeTV and Faxon for donating your time to do this Q&A!
Thanks to Nathan and Karl. Diving deep into barrels is teaching me a lot that I never knew before.
These Q&As are fantastic. A very easy format to get incredibly interesting technical information.
This discussion on barrel profiles just confirms what I've always thought: the M16A2 was not, generally speaking, any actual improvement on the M16A1. Maybe the change in rifling twist was an improvement, since it allowed heavier bullets to be used, and maybe the reinforcement of the lower receiver where the buffer tube attaches was also an improvement, but that's about it. When I was at Fort Benning in 1996, I was briefly detailed to work in the armory there, and I got to know some of the civilian workers, who were mostly ex-infantry themselves. One of them, I remember, was very outspoken in his opinion that the A2 was inferior. He disliked the extra weight; felt the more complicated rear sight was unnecessary, and most soldiers would never use all that adjustment capability; and he thought the replacement of full auto with the three round burst was a bad idea. I agree with him in all points. The extra weight added to the barrel was all up front, and it made the weapon balance worse, and made it more of a pain to carry on long marches. As discussed here, since it left the portion under the handguard thin, it simply moved the weak point in the barrel backward to just where you DON'T want it. As for the rear sights, I certainly found neither I nor anyone in my unit tended to mess with the rear sight once zeroed -- given the ranges at which we were likely to engage, and the relatively flat trajectory of the 5.56, there was just no need, and the older A1 rear sight would have been just fine. I am utterly unsurprised to learn here that these changes to barrel profile and rear sight were driven by match shooters who wanted something better suited to a target range. The US military has a long history of letting things like that creep in during peacetime. It also echoes the way they put a target range rear sight on the M1903 because of the input of Camp Perry shooters into the design, and found, in WWI, that it was not a good battle sight at all (the M1917, which more of our troops carried, had a simpler, and far, far better one). Plus ça change, plus c'est la même chose.
Darren O'Connor -very much agreed. When i was in LE (20 yrs) we got some milsurp A1's from DRMO in early 2000's. Those sights made sense- windage on rear sight, elevation on front. More rugged and soldier proof. The A2 micrometer rear sights, which i had seen on Colt Hbar sporters when i worked in a gun shop years before, were too complex. Supposedly the Marines demanded the changes because they felt they could get more accuracy. But your point about sights seldom being adjusted after zero is dead on. Maybe on a KD range u might dial in some elevation at 500 or 600 yds, (assuming 300 yd zero), but u have to remember to take it back out. And u have to know what to dial in. And u won't have time in a combat scenario to do all that; everything is done with holdover. An infantryman is not a sniper who is trained and experienced in dialing in adjustments based on known performance. Seems to me like the whole thing is kinda like the chrome plating of mess kits. Thank you for your service.
Ok guys,
I read the reports on the M16a2, before going into the Marine Corps in 1982.
The heavier barrel and the sights on the a2 are just for range time. Everyone in the development of the a2 were match shooters. Twelve Marines, two Army Sgt.'s(one I believe a E8, one E6), and two civilian match shooters(from the NRA). A Army Colonel at the Pentagon put in his two cents(not even worth it) and gave us three round burst. Oh, and the longer stock, all for match shooters. So the Corps fucked it up.....
And I being MARINE, just said that....
They also gave us the better flash hidder many be.....
Square front post, many be.....
But that where the shit came from.......
That all being said,
I use a AR15a2 as a CMP match gun(mein being 9 lbs). And do carry it, at times.
But I do think the a1 was better in many ways.......
The barrel twist should have been 1 in 9, but match shooters wanted the 1 in 7(is mil spec) 1 in 8 is what most M16's are.......
@@knutdergroe9757 I heard the 1:7 twist was mainly because of the M856 tracer round, and a desire that it should be able to use it. 1:9 won’t properly stabilize the M856 tracer, IIRC. It will stabilize the M855 round, and is more accurate doing so, but it wouldn’t stabilize M856, and especially in the pre-IR laser days it may be the case that tracer rounds may be fired from a rifle to mark out targets, or simply that it is the only ammunition available.
The Faxon Barrels that were sent to me by Faxon were outstanding in quality. Even for Blem barrels which is what they sent me for testing.
Our pleasure to be of service.
@@FaxonFirearmsOfficial I'd love a blemished barrel from you guys any thing to keep the price down on a quality ar build on a budget
Thank you. If you keep making 'em, I'll keep watching 'em.
Wow... informative. Knowledgeable and articulate guest.
This is 'firehose' ballistics education! Great stuff! Keep it coming!
I love this series Karl and Ian, thanks so much for the interesting discussions.
Love this series. Very nice for faxon to loan one of their guys out. Thanks Karl and faxon.
Our pleasure.
I can feel my brain growing!
I'm glad that finally, someone stated that fluting actually weakens a barrel. I've seen so many sub-par companies say that fluting actually strengthens a barrel. How the hell did they come up with that conclusion?? When you flute a barrel you are *removing* material from the barrel, so you are inherently making it weaker. Granted it's not enough to make a barrel grenade on you, but it still is a weaker barrel.
GREAT video series. Tons of appreciation to Faxon for sharing the indepth information with us.
From this series alone I will be making a contribution to your channel. I've learned a lot from these discussions. I wish that more content like this was available to people such as myself.
I love all these Q&A's with manufacturers. It has really made me think differently about firearms and how they are made.
I absolutely love these in depth technical video's, and I don't even shoot.
Not all what has been told was new, but all of it made perfect sense with only a rudimentary knowledge of physics and mechanics.
This makes great video, Karl! I'd like more, if possible!
Thanks, Faxon! A question for the next Q&A:
Are pencil/lightweight barrels suitable in a dedicated suppressed gun? In other words, does the cantilever weight of a suppressor negatively affect accuracy in pencil/lightweight barrels (in a civilian semi-auto role)?
Good question for another installment.
I'm rewatching these having just picked up a Faxon 16" pencil barrel for a WWSDish build.
I'm rewatching this after picking up an enhanced lightweight fluted barrel from bcm.
Great work Karl! Really enjoying these interview videos, as it gives a WHOLE lot of insider thought and information.
As someone who owns and built an AR15 using a 14.5" Faxon Ultra-lite pencil barrel, w/ perm G6 FS installed, I can say they make a great product and it has held up excellently in my use all the while making the 1.4 pound less weight a real benefit without sacrificing the accuracy I want, (when compared to other 14.5" w/ perm G6 installed ARs I own).
Love these talks and discussions and I definately love my Faxon barreled AR.
GREAT INTERVIEW! Thanks to both of you for this video!
Thank you gentlemen for an explanatory discussion, well done.
Love this kind of content! Honest to goodness, real information is too uncommon in the world of internet gun content.
Im nerdimg out over all this...good information
While I do really enjoy all of the videos here on Inrange; I enjoy these types of videos the most. It is very interesting to watch these technical types of videos, learning how people over came small or large issues. Please keep up the great work with these.
Please consider making more videos like this about the factors that go into producing firearms. It's interesting and informative in a completely different way compared to the videos you make focused more on the end-user perspective. I realize that material choices, manufacturing processes, and other practical considerations for a manufacturer are nerdy subjects outside the general gun user's interest, but it can't hurt to ask!
Really enjoy these Q & A sessions. Keep them coming!
So much good info here. I kind of understand the basics, but the great explanations have added to my knowledge immensely. Thank you, Nathan!
These videos are so informative I watch them over and over.
The Gas block on an m-16, being designed to fail before the barrel is so smart. Still being able to shoot single action and replacing the part instead of an entire barrel. Genius.
*single/bolt? don't really know what to call shooting a round and then racking the bolt manually each time on a semi or fully auto rifle, due to semi or full auto not function. Like on a yugo sks, when using the grenade launcher.
Single shot bolt action would be about right.
Thanks Karl and Ian.
Nathan, we are really enjoying this over on 308ARdotCom!
Dave Lutz, the USMC's project manager for the M16A1 PIP, has pointed out that if it had been up to Marine match shooting community, the M16A2's barrel would have been a full-length heavy profile. A long-time member of the USMC marksmanship team, Maj. Bruce M. Wincentsen. was in charge of operational testing. He went out his way to try to get his test personnel to try and bend the A2-profile barrel during bayonet drills. This escalated to the point where they were bayoneting telephone poles. However, the M7 bayonets gave up the ghost before the A2-profile barrel.
Lutz would later note that what they thought were bent barrels in drop gauge tests were more often than not excessively fouled gas ports. Copper fouling would build up on a burr if the edge of a land had been clipped during the gas port drilling process.
"there's no absolutes in the world" is an absolute statement...
Love this stuff. Absolutely love the knowledge dumps.
Makes me excited to build some AR's for certain.
Wow... Soooooooo much knowledge... Sincerely Pray There Will B More to Come....
Thanks once again for this (series), Karl (and Ian...) - this is awesome info that I have no reference for otherwise, and as an individual who 1) wants to know the most he can about anything scientific, "gun" or otherwise, and 2) builds his own ARs and M1As/M14s "from scratch", this information is absolutely amazing and unprecedented. Yet one of many reasons I am signed up with your Patreon account; keep it up! :D
A couple of question suggestions for next time:
•In a recent live-chat, Rob Ski from the AKOU was asked about nitrided barrels v. chrome. He said that, while a chrome-lined barrel can wear over time, he had noticed that (in his experience) the nitrided barrels seemed more consistent initially, but that there would be a point where the accuracy would just drop off sharply and the barrel would suddenly turn to $#!+. I assumed this was due to reaching some kind of stress-point, probably due to heat, but now doubt that after your last Q&A. Over on that other channel, they like to do a lot of mag dumps and then check for accuracy, POI shifts, etc., but given that you stated that no one could shoot fast enough to heat a barrel like full auto fire, would you assume such a sudden drop in accuracy would be due to faulty nitride treatment, or would you expect some other cause?
•Speaking of which, while I doubt anyone using a bump-fire stock cares too much about accuracy when dumping ammo, some of the emerging "binary" triggers are claiming faster-than-full-auto capabilities - so I would assume the same wear and heat rules apply as F/A (if used consistently in that manner.) Correct?
•I was aware of what you were saying about barrel length and accuracy, but maybe not to the extent you stated. I've always been a little mystified by the apparent accuracy of the Russian VSS "Vintorez" and family of weapons [my personal grail-gun] given it's extremely short barrel as seen with the suppressor off. Some of that magic is bound to get into the cartridge design, and that element may be too far afield for this chat, but I'd love to ask if (either of) you are aware of any accuracy voodoo you could comment on there? Maybe twist-rate or whatever?
•And given what you've discussed about fluting, etc. (and given some oddball builds I have planned) is there any real difference in effect, or any unique qualities (other than manufacturing concerns) between old-West-style octagonal barrels and round barrels of similar average girth and weight?
Thanks for any information on even one of these, or if none, then still thanks for sharing these conversations and interesting info in general.
Cheers!
Lots of good questions in there. We will have to add them to "the list".
Righteous.
There is so much great info in this video. Thanks for taking the time to do this. I look forward to some more of these vids
I can attest. I have a Faxon 14.5" pencil barrel that I put together in an ultra light 5.56 AR. It is very well made, accurate, and very light. I took it to a practice Highpower match, it held accuracy at 200, 300, 600 yards. While, obviously not competitive for actual Highpower shooting, it did impress me greatly with practical performance, easily placing m855 ammo into less than the size of a man sized target. I was using a aimpoint PROTECT at 200, 300, and KAC rear/Daniel Defense fix front at 600 yards. Heat did not appreciably effect consistency in my estimation.
Amazing. Please keep these videos coming! I could listen all day!
I learned a lot in both sessions. The biggest thing I learned, is I dun goofed when I chose the Faxon Gov't profile barrel over the Gunner one (18", rifle gas). :(
*sad trombone*
Same here exept it is 16" mid length gas. I was on optics planet and i thought the socom profile was one thick barrel but when I saw that it is thin and goes thick after the gas port I goofed too but I will use it since I already have it.
Barrel length - mind blown. BOOM. Great vid - just awesome.
Thanks, Nathan! I definitely trust Faxon more after listening to you!
Greatly appreciated 👍 Oorah & Carry On !!!
I don't know if it's been mentioned already, but the 14.5" barrel was chosen for being the shortest compatible with bayonet use, not for noise levels. The government barrel profile is for compatibility with the M203 grenade launcher. The M4A1 required slab sided cuts underneath the handguard for that reason.
Not for the bayonet,
Think about John Brownning.
He figured it out,
You need at least four inches past the gas block. To insure consent operation of the system. At more that(ie the 16 inch barrel) you increase the amount of gas into the system. Gas block placement (without a adjustable gas system) is critical, for long and high value use.
Two years late to this party, but for general information regarding the Marines using rifle barrels as a tool: The old C-ration cases were bound with wire, and it was easy to use the M14 rifle muzzle to twist and break the wire, with no damage to the barrel. As discussed, the thinner M16 barrel would bend when this trick was tried, so the forward barrel was thickened. Proper instruction helped, as well as going from the C-ration to MREs in the glued-closed cases.
Great video.
Barrel rigidity increases with the 4th power of diameter and decreases with the 3rd power of length. In other words, doubling the diameter makes it 16 TIMES stiffer, cutting length in half makes it 8 times stiffer. Moral is if you're going with a short barrel, it can be very stiff without needing a lot of diameter.
It also shows the very steep diminishing returns on long barrels. Long is heavy AND needs to be thicker (so even heavier) to get the same rigidity as a medium or short barrel. Going from 16" to 20" requires an 18% increase in diameter to keep the same stiffness, and 24" needs a 35% increase!
Thank you Karl and Nathan! These are great Q&A's.
If I nitride coat my butt, will stuff come out of it more accurately?
Yes. Definitely. ~Karl
Hostile all depends on your fundamentals of markmanship...
hui Heavies follow through is important. Ever got up while it's not done coming out?
No, but you'll become a hardass
No...inconsistency in load setup
Can you discuss the effects that suppressor has on a barrel. also the most advantageous profile to use with a suppressor. Great content!
Oooo. That's a good one too.
I'm really loving these videos. I have a Faxon 18" Gunner profile barrel. Shooting for groups I can manage to get just over an inch on average. I'm sure that if I were to shoot a bit more and hand load I could bring that under an inch.
Great stuff guy's. Please do more of these.
Thanks for the depth guys. Very interesting and informative. Now I need new barrels!
I have a Faxon Firearms mid length gas system pqp nitride socom profile 18 in. barrel on one of my ar builds and I love it. shoots about .75 moa groups just using some perfecta .223 remington 55 grain fmj ammunition. I built the rifle specifically as a kind of jack of all trades rifle with recoil control and balance being some of the primary objectives, which is why I chose a socom profile simply to keep the weight up front and use of an adjustable gas block from slr rifleworks. The rifle is phenomenal and the barrel is one of the best I've used. Recoil is like a .22 mag and keeps me on target for fast and very accurate follow up shots.
Ive heard that the m16a1 barrel bending and drooping was because there was a burr left over at the gas port that was caused from dull tooling not being scheduled for replacement soon enough. So when being cut it would leaf a little burr at the gas port that would cause friction and excess heat at that one spot. It would cause drooping. So they made it thicker right there but it became the a2 profile. but later on they found it was the burrs not the profile.
Good stuff. I have to say when I first started researching barrels before my first build, I was looking at those government profiles that are fat and then skinny in a place that obviously should not be skinny and I did not like it.
I ended up with a 14 and 1/2 middy from Daniel defense, it's a pencil barrel which I really didn't want a pencil barrel but I got a really good deal on it and now I love it.
I would totally buy a barrel from faxon.
The only thing missing from the fluting topic (which was interesting) is some sort of quantification of how much more quickly a barrel will return to the cold zero after being overheated. So, using your WWSD test of a quick 30 rounds to test the zero drift I'd be curious to hear if a fluted barrel would cool down a minute faster, five minutes faster, etc. And, how long that test you did would keep something like an A1 barrel out of zero. If you gave him that question ahead of time I wonder if he could put some math to it.
I love my Faxon pencil barreled AR, it so light.
Excellent !! Learned some things I didn't know I didn't know.......Most Cool !!
Great vid from a good company. I actually own a pencil profile from faxon seems to work great for my use. The barrel and their lightweight carrier group are the core of my 5.25 lb ar for my wife. She is a small statured woman and seems to handel this combo well.
Send photos, please!
I watched the first one. I enjoyed it. I wasn't going to watch the second one, just seemed it might be a little boring or redundant. I watched it. I am now hooked, part 3, 4, 5???? Good stuff.
Looking forward to part 3!
You guys mention full auto mag dumps in military application. I think I only used burst once in training, when they told me to. As a combat engineer, I only used a bayonet on a rubber duckie in training. I don't think I ever fixed a bayonet to a rifle. Not debating the actual reasons you guys stated. Just poking fun at the reasons. Great episode! When I get caught up on bills, I want to pick up a pencil barrel. Thank you!
This a great series giving great information. Thank you all for doing this.
thanks inrange & faxon this was very informative.
Thank you both for the content.
great job everyone and Nathan this info is very welcome, thanks!
thanks for this video very informative
Watched these videos... Now somehow I've ended up with two Faxon barrel builds. Haha
Shooting .75 moa with handloads. I wasn't sure if I was even that good of a shot.
For some reason I've never checked out Faxons barrels. I pictured them being some outrageously priced $400 Noveske barrel. Not at all, very reasonably priced. I think I have to check one out.
Thanks!
Thanks guys! I learned alot and am following the channel, in hopes you enlighten me more!
Thank you for an interesting and very informative video. But I have a question; Can fluting increase a barrel's rigidity for a given weight, temperature, length, and so on by increasing its (maximum)width? As in, if you took two identical barrels and added the same amount of material to each, but in one you increased the thickness uniformly, and in the other you added ridges, the latter could be stiffer, depending on the ridges' shape and arrangement? The principle that H-beams and the fullers and raised ridges on swords are based on seems to be in play here, but I'm not sure of the direction it works in in this case.
You are on the right track. A fluted barrel will be more rigid than a barrel of similar weight in just a round OD.
I really enjoyed these interviews.
Please do more parts very informative thank you!
Great video great information
Very informative video thanks, gonna watch them all
What awesome information.
These are great interviews
Thanks guys! Great session!
Lot of good points. Reminds me a little bit of the knife world. Almost no one can really tell the difference between super aogami steel and 5160 when either a heat treated properly. You need to operate like a machine to go beyond the qualities of even quite basic steel.
Would loved to have heard what the Faxon guy had to say...
Great series! Learning a lot!! (Thanks Faxon!) Keep going!!! :-)
Great series here.
What are the pros and cons of housing a barrel in a rigid shroud that puts the barrel in tension, as on a Dan Wesson revolver? What is involved in optimizing such a design?
correct me if I'm wrong but I thought the 14.5 barrel was decided for bayonet use with the original carbine gas system.
Great information thank you
So Faxon's position on using 3rd party Nitride vendors can be summed up with one of Ronald Reagan's favorite Russian proverbs; "Trust, but verify" ("Доверяй, но проверяй")
Da, Comrade.
love this cause I am going to build an AR15 here soon thus the info provided is awesome from this video and the last
On the SBR's and powder burn rate is why I've chosen to go with an 11.5" PSA Pistol in .223/5.56x45 NATO. Most everyone else is going 10".
Excellent video guys.
Thank you guys very educational.
I really wish barrel manufacturers would make a barrel that is thick at the rear and standard M4 profile starting at the gas block(on carbine-length gas system). I went with a M4 profile on my carbine-length AR-15 simply for aesthetics, and I doubt I'll ever put the rifle through enough hell to have it make a difference, but it would still be nice to have the look of the M4 profile without the huge flaws in the design.
Nitride definitely does make a significant difference, however, one that's done well vs one that's not done well makes a world of difference.. if you want to break it in slightly first then clean and nitride it you can.
great tec video love this sort of thing thanks Faxon thanks Karl
Love this series!