Faxon Q&A #3: Twist rates, stress, break-in, gas ports & more!
Вставка
- Опубліковано 29 сер 2024
- You asked for it, so here it is. Part 3 of our barrel discussions with Faxon. In this one we jump into twist rates, stress relief, lead lapping, break-in, gas ports and more.
00:41:11 Deep dive on twist rates.
How are they determined?
How are twist rates made?
What is ideal for my caliber / bullet?
What is twist rate?
55 grain bullets in a 1/7?
How is twist rate cut into a barrel?
20:46:00 Stress relieving
What is “Stress”
What to look for in properly stress relieved barrels.
Methods of Stress Relief (Thermal vs. Cryo)
Discussion on Cryo treatment in general
How do you know stress relieving worked?
28:35:00 How good were the best barrels from “old times” when compared to the modern era?
31:16:00 What is lead lapping?
32:52:00 Discussion about barrel “break-in”
What is it & what does it do when they break-in a barrel?
What about treated barrels like Nitride and Chrome?
Barrel break-in for average shooters compared to niche need shooters like bench rest competitors?
43:45:00 Gas port sizes and barrel location?
Rifle length, mid length, carbine length?
Gas port cutting location, between or on lands and grooves?
InRangeTV is Patreon supported!
/ inrangetv
InRangeTV T-shirts here!
shop.bbtv.com/...
A pleasure to join InRangeTV again! Look forward to more awesome questions.
Faxon Firearms what are your thoughts on 6.5 creedmoor and barrel life. Particular stainless steel vs carbon steel?
Thanks,
Mike
We're honored, sirs. Thank you!
Flytyer- Great question. I don't think we covered materials in great detail so it will be good to rehash in another.
Okay, I will be awaiting that video!
Thanks
I learned about you guys here on InRange and bought your 10.5" 5.56 NATO barrel in 4150 QPQ and it is awesome! Shoots great! I will be buying from you guys again.
Another hour-long highly technical gun-related Q&A? Yes please!
To shed light on your 1/9 stabilizing heavy bullets mystery...
It has to do with velocity.
MV x (12/twist rate in inches) x 60 = Bullet RPM
Quick Version: MV X 720/Twist Rate = RPM
MV = 2800 FPS
1:8-Twist RPM = 2800 x (12/8) x 60 = 252,000 RPM
MV = 3200 FPS
1:9-Twist RPM = 3200 x (12/9) x 60 = 256,000 RPM
As you can see if you launch a bullet faster in a 1:9 it can actually outspin a bullet fired slower in a 1:8.
This answers the short barrel 5.45 "mystery" that was mentioned as well. The longer barrel does not need a higher twist rate (to a degree) because it is launching the projectile faster, thus spinning it faster.
Thank you. I was pretty sure Velocity was the missing piece, but wanted to double check in the comments. The math was very helpful.
Watched a Hornady podcast the other day and it was mentioned to never go over 300,000 rpm with any bullet.
The quick formula is what i use with my new 1:8 22-250 barrel.
Guys, with your contents you went from costing me 2 bucks a month to 5 - because I really love your content and you breached the line between entertainment and education twice.
I keep discovering content of *this* quality and over and each time I'm all about throwing money in your general direction. Please stop, not.
This is excellent marketing for Faxon (Not implying this is why they're doing this) both because they can speak to the quality of their barrels and mastery of the technical art of barrel making, as well as showing us just what kind of an awesome company they are.
Agreed! Barrels seem to suit them much better, and I'm tempted between a Criterion barrel and a Faxon barrel for my next build.
@@jameskachman3692 did you reply to urself??
Of course Faxon is doing this for marketing. These discussions are extremely informative, and they demonstrate their breadth and depth of knowledge regarding barrels.
@@whippetcanister4278 There may have been a reply that has since been deleted.
I love Ian's face when Karl is talking about Tula 5.45 vs. 5.56 was hilarious. He is definitely thinking, "Good. Gooood. Stir the pot."
This is the difference from knowing your craft and taking the time to learn vs just collecting a paycheck . This dude knows his shit for sure . Awesome to hear someone who can answer these questions and actually makes sense .
Nice video Bro
This series leaves a good taste in my mouth for Faxon. I now plan on buying their Gunner 20" soon. Nathan is just a good dude telling us factual information impartially. If a company has a product worth your time and money they will have no need to shill or manipulate/deceive for it, just simply explain why they made it.
Just bought a Faxon pencil barrel for a project I have been slowly working on. I'm not saying these video sold me, but lets say the lads down at Faxon have my confidence that they are making a quality product!
How has it been?
4 years later, watched this again.. One of the better in depth series on this channel. Thanks InRange and Faxon! One reason I like Faxon is, like Kreiger and Douglas, they aren't just manufacturers they are enthusiasts and are passionate about their product. They also do it at a very good price point, which is awesome.
Aside: Overstabilization is grossly overstated, as they all said. One of my best shooting loads in a 16" 1:8 5.56 is a 40 grain v-max. The spin DOES make the terminal effect just a touch more impressive.
I love these videos. Please make more deep dive videos.
Great info on the Miller formula.Since watching this I've been using it for my subsonic 7.62x39 handloads.
Gives me the range of velocities l for which the heavys will stable and safe for my silencer.
Someone needs to make an incredibly sarcastic barrel break in video. just crazy crazy recommendations and a totally straight face.
My first AR barrel = faxon barrel. After watching this, my purchase has been reaffirmed. TY all for this great information.
Please keep these educational videos going! So much info in here...so much of it needs to get to the average consumer to stop hearing the same wrong comments on forums everywhere!
I have two Faxon barrels; one in 6.5 Grendel and one in 7.62x39 (both "Gunner" profile) and they're both excellent performers.
Coupled with their willingness to sit down and talk frankly in an engineering sense as to *why* they make the choices they do in their product line is refreshing, and inspires confidence in their products.
Very informative. It confirmed a lot of my thoughts and made me consider things I hadn't thought of. This string of videos is great. Although it may seem a little dry, for "the gun nerds" it is edge of the seat spectacular.Thank you and keep this kind of content coming please.
Regarding barrel break-in: Most people have no idea what they're talking about (or what they're doing) for one simple reason: They don't have a borescope. I have a great borescope from Hawkeye (with video it cost me over $3k). It's AMAZING what you can learn by actually LOOKING at bores. The very bottom line is: if you don't see copper fouling you don't need break-in, and what you're trying to DO when you're trying to break-in is remove copper fouling because THOSE are the places where the bore is slightly rough. You take the copper fouling off, and then the next bullet can polish over that area, etc. If you have a bore scope the entire issue is EASY; if you don't, it's like wizardry; it's like being blind and trying to describe an elephant. I agree with this guy that the vast majority of people don't need to bother with breaking in barrels -- and indeed, the vast majority of people would do more harm than good the more "interested" they are in shoving cleaning rods through their bore. A bore snake is a very good way to clean a bore in a practical way -- without damaging it.
Great video! Love this stuff and I can't say that enough.
I know for me, Faxon is now going to be where I get my barrels for my new rifles.
Thanks! We're honored. -Nathan
I was going back and forth between them and another company for my lr308 build until I saw this series. Definitely cemented my decision.
Thank you, Sean!
Was going to buy a spikes barrel but this series has convinced me to go to Faxon. Thanks guys - awesome series glad to be a Patron
I'm a patreon supporter and this series is why. As someone interested in all things firearms, from metallurgy to history, pick a subject, this channel and FW bring so much joy to me. My wife thinks I'm a total nerd tho.
The next session should be do's, don'ts and myths of barrel cleaning.
The thing about chicken bones is that most people nowadays use bones from farm raised chickens, and those just don't have the sympathy that you need. Real operators use fresh jungle chicken.
For the record the Tubb's lapping bullets are to be fired at low velocity. The instructions tell you to use a very light powder charge. I used them one time on a cheap non-chrome-lined DPMS barrel that was new and not very accurate and it actually made an improvement. But the real lesson is to just buy a better barrel.
The best use I've found for them is with cheaply made Soviet-Bloc guns. Worked miracles on an SKS that resisted any other attempts to make it shoot straight.
I have used Tubb's on 2 M1A's and a chrome-lined POF-USA AR barrel, and of the 3 my Springfield M1A Squad Scout went from Meh to Awesome while the other 2 I honestly can't tell (and it's possible I hurt accuracy, as I admit I'm not normally a very good shot to begin with...with the exception of that Awesome M1A, at least).
Amazing discussion of modern firearm design and function for the average user. Thank you for the knowledge transfer!
A couple years ago when I was shopping for a new 308 bolt action, I ended up getting a Tikka T3 CTR 308 with a 1/11 twist rate. It seemed like an interesting compromise. Too bad I don't have a chance to do long range shooting in western North Carolina, I envy you guys out west.
Guy's I'm on the third video so far and these are the most fascinating series of videos I've ever seen, thanks to all for the education.
14:34 - such a perfect question, Ian. I was wondering the exact same thing, and was floored when you asked it right at that point. There has to be a good reason why some barrels stabilize things that they should not.
Thank you for this awesome series of vids! Great content. I've always been fascinated with all this info I have Experience with a little bit of all these topics and this really brings it all together, thanks.
for someone who is thinking of building a ar this has been great. love the stuff on here and gives me a lot of useful information.
Although the material covered was technical, everyone explained it well. I learned a great deal and was particularly interested in the 223/556 twist rates. Great video!
Great content. I had pretty much found out through different sources that barrel break in is bs, with the exception of certain special purpose high dollar barrels. When i got my new Bushmaster 16" in 2006 or 2007 for a patrol rifle, i think i did clean it after 50 rounds, and maybe after 100, but i didn't worry about it. Shoots fine. Almost all of my rifles have been bought used anyway. Keep up these types of videos. We love them.
"Incredibly valuable" indeed. These Faxon vids alone are worth the annual cost of being a patron.
This is one of the most informative videos I've ever seen, thank you guys for putting out this kind of content.
I love those conversations. These and the Hill & Mac interviews are extremely interesting and informative. Thanks for the work you guys do.
This has been an excellent series. I have chosen a faxon for a rebarrel and a big part of that choice has been this video series. Thank you for sharing !
Thank you for the time to help clear up what many dont understand.
I see questions on 300 Blk all the time on twist rate and I jump right in and push for the 1x7 barrel if subs are to be used at all.
Its a easy to understand way of explaning the twist rate vs velocity.
So much amazing info here. Thanks for taking the time to go over this information.
New sub. Great conversation to explain things simple enough that even if I was new to the firearms world,I would understand.
The Bear line of ammo from Barnaul seems to be significantly more consistent for a just couple pennies more per round vs. Tulammo. Not going to hate on dudes that shoot Tula. Whatever gets people out shooting and having fun works imo. My go to Russian ammo is Golden Tiger. That stuff is just awesome for the price. It's hotter and more consistent than any other Russian ammo manufacturers. It's also made on the most modern tooling of all the major Russian ammo manufacturers.
Love this, THANK YOU for these videos, they're immensely helpful to us newbies. Faxon, you rock!
This is great tech info that can translate to daily shooting and long term use and longevity of our rifles and firearms. Thank you
Bruh this serie is gold
very interesting series of q and a videos, very nice of that guy to take the time to answer all the questions, my next barrel will be a Faxon one for sure!
What a great conversation, I really enjoyed these 3 chapters. Thank you.
The chicken bones told me that you have to break in the barrel at midnight on Valpurgis-night with a goat and in the moonlight
Yes but only red, latex or tiger-motiv.
as for the M855, a 1:8 twist is enough. but someone thought it was a nessessity to shoot the M856 tracers out of the M16A2 (and later models) so they adopted 1:7 (just like the Minimi/M249. The M16A2 was compiled of a lot of less-than-ideal/should've-been-a-target-rifle changes and features, barrel twist being one.
again very informative video love these thanks @Faxon Firearms &Karl, Ian all the best from Scotland
Some questions for a future video:
- What are the advantages and disadvantages of Mid length and Rifle length gas systems on an 18" AR15 barrel?
- Explain headspacing and the dangers of having too much/ too little in the AR15.
- The differences between the 5.56 NATO chamber and the .223 Wylde chamber. Why does Faxon use the 5.56?
Good ones!
I really enjoy these type of videos, always learn something new with each one.
Just watched esp 1. Now watching esp 2. Gonna watch all to learn. Thanks
after watching this video that is now 4 years old im glad i chose to buy the faxon 6mm arc barrel for my new build.
Thanks so much for these Q&A's. They clear up a lot of misconceptions and help make better choices. I'm already putting my next build together in my head. Say, when will the fiber rails be in stock??? :-) I guess the problem will be keeping enough product in stock. I'll have to keep going back to the website and checking availability.
Best series of vids I've seen thanks guys. Thanks Faxon
thanks again guys. great series. Nathan, your the man and so are your barrels!
Great information from experts.Lots of thanks 👌👌
Cryogenic treatment actually creates dramatic changes in the grain structure of steel as well as stress relieving.
This offers substantial improvements not just in thermal stability, but in reduced friction and wear resistance.
Great video with great information I knew there was a lot to it but had no idea and I sure am glad I never tried those lapping bullets in my rifle.
thank you i will only buy faxon from now on cause he took the time and did this
Love nerding out on this stuff!
Nathan, can Faxon make a series of videos showing how barrels are made, stress relieved, and nitrided? Mainly to show shooters exactly what the process is without giving away company secrets of course. Most of us gun guys would really appreciate that.
We may - certain things we can talk about but much of the how is a company secret. Until then, we'll allow the barrels performance to speak for us.
I would love to hear about progressive rifling and what the benefits and trade offs are for that type of rifling.
1 in 9 can sometimes stabilize 77 grain, IMO, because it is right on the cusp of stability. If you plug in the values to a Miller stability calculator, the result will usually be less than 1.5, but above 1.2, so it might fly well. However, if you start changing temperature and pressure values, stability is lost. For something like a 77 grain in a 1 in 9 twist, it might be close to 1.5 at 80 degrees Fahrenheit, but groups open way up at 40 degrees. Height above sea level has the same effect. A 1 in 7 over stabilizes 77 grain a bit, so they are still very stable down to 0 degrees f and even below.
Thank you for the info for breaking in my new Faxon 18" gunner. Will just shoot, clean and enjoy.
Do the dew Ian! Great video as always! Love these deep dives :)
Love these Videos even after all this time lol 😝
Another great video. I love this series keep up the great content.
I will be getting some Faxon Barrels. 🙂
I like that IV8888 Rangeday t-shirt! Wish I could have gone there!
maybe I am just a nerd, but I find these videos very interesting. thanks
Good stuff!
GREAT SHOW..... Thanks for Sharing.
Good stuff guys. Thanks for the information.
Love those! You should release them as podcast too.
We do release these as podcasts to our Patreon supporters. ~Karl
Fair enough.
I really enjoy these videos.
part of the formulae for twist rate is velocity, because the rotational speed is dependent on it.
Nothing's for sure though, I have a 1/9 twist barrel that shoots 75 grain bullets really well.
Another factor involving twist rate is little known -- I read about it in the books put out by the ballistician from Berger bullets (can't recall his name right name, sorry). It's particularly important at long range: The issue of the TAIL of the bullet following the POINT of the bullet. If you picture an arrow flight, upward and then down, as the arrow turns downward the fletched end nicely follows the tip. In bullets with too fast a twist, the bullet (from gyroscopic forces) will want to maintain travelling "horizontally" (assuming the barrel was originally "horizontal"), and so as it begins a strong downward curve at long ranges it won't be POINTING in the direction it's travelling -- and this makes a MESS of B.C. This is actually an extremely complex problem which nobody really knows the answer to exactly. The bottom line is -- at least for long range shooting -- too fast a twist is bad, even if you're not seeing any evidence of bullet instability or breakage from too high a rate: you will not end up with the trajectory that your ballistic calculations lead you to expect.
For anyone wishing to convert from imperial to a logical measurement system, an inch is *defined* as 25.4 mm.
Yes I always thought barrel break in was B.S. thank you guys.
Great one guys, very interesting.
great stuff!
BTW new Faxon barrel and other goodies inbound... :)
I used the Miller formula to calculate the stability factor for a 5.56 mm 77 gr. bullet with a muzzle velocity of 2700 fps (assumes a 24 - 26" barrel) at a 1:9 twist rate and found is was well over 2.0. I had to reduce the velocity to 2300 fps to get close to 1.5. So, a 1:9 twist should stabilize 75 and 77 gr. bullets just fine as long as you keep the velocity up with a longish barrel.
After being a machinist for 15+yrs dude knows his sh*t. I won't use a bronze brush on my barrels. I shoot and let the copper fill in any inconsistencies. Depending on coating, just like he said. Take care and clean when needed. You don't need 10 different solvents or oils to clean a firearm. Most problems I've seen people have, is controling gas vs mass(spring & buffer weight). Especially with self-built, wildcat calibers and short barrels
For a given mass, a longer bullet requires a faster twist. An analogy is that a longer bullet is simply easier to tip over (to destabilise).
For a given length, a heavier bullet requires less twist. An analogy would be a heavier bullet is harder to tip over.
The projectile in the tracer round (FN L110, or US M856) is both longer and relatively light (63.1 and 64.7 gr), this is the reason for the 1:7" twist barrel, not the weight and length of the ball round. The projectiles SS-109 and M855 ball are both over-stabilised by the 1:7 twist.
For note the projectiles of the FN L110 and US M856 rounds are not exactly the same, nor are the projectiles SS-109 and M855 ball rounds.
Karl, you were great on P&S the other night! You should do that again soon.
I'd really like to see a Q&A video on 308 AR barrels and what differences and strengths/weaknesses are in production and usage of them.
Interesting choice of topic. What questions are you looking to have specifically answered?
Things like barrel material. The world of 308 AR's is sort of a mystery as to what works or what is optimal or not optimal. Take for instance stainless/nitrided vs 4150 CMV/nitrided. How do they perform when they heat up? Which one has longer barrel life? Which ones tend to me more accurate? What are your gas port sizes and how do they affect performance with different ammunition?
Shooting a bullet with lapping compound is most common on hardcast bullets and revolvers, usually magnum revolvers with people who hand load. Usually to match your bullet mold to your barrel
No, slugging is to attain the proper size for the bullet you need. Fire lapping (which is using a mild cutting compound on a bullet) is/was used to iron out any bulges or inconsistencies in revolvers, usually in the context of bulls-eye style shooting. Its not really needed anymore, but back in the 50-80s it was more common. Occasionally there were bulges in the barrel from stresses from manufacturing, normally you wouldnt notice, but if you shoot cast bullets where they could be effected more and you knew you were using a very consistent diameter bullet, generally if you cast your own. You could fire lap a barrel that wasnt shooting up to snuff and then cast a bullet ideal for your now inconsistency free barrel.
With modern manufacturing its a very rare thing if this was needed, and youre better off just slugging your barrel, sizing your bullets properly and pressing on. I just figured it could be a good piece of info to have in the comments so I added it.
the drilled gas hole in the barrel. There is always a significant burr at the end of the drilling process. Is this of consequence? Is the hole drilled prior rifling? I don't think that lapping a barrel would remove a significant amount of the burr.
Excellent Q&A session.
Ian asks good questions, he thinks like a machinist.
Great stuff, I hope to see many more discussions. One question I thought of which was not covered. In gas port erosion, is there a difference between Nitride, Chorme lined, or stainless. If so what is it?
Personally I have learned ALOT of barrel knowledge in only a episode an a half, I'm halfway thru the second (😅😏🤫) an alot of my questions have been answered. I'm not gonna be that guy that came here to engage in a pissing contest because I am dead set on a "my own beliefs" with comments. I'm here to say thank you for these videos for us common folk peasants who are pour in some knowledge an money I suppose an smell like sour milk. We all should be greatful for not only the technological journey of firearms weather it be platforms, triggers, barrels and all the different treatment processes you can chose an argue about, ammunition and it goes on an on. But like I said we should feel so lucky to how we are learning these things these days. If I was to think back when I was a young teenager in the flat farm lands of California in the early 90s hunting coyotes an wanted to learn something or if like ANY teen had questions to ask, you would either find a book if possible or ask somebody an take their word on it when in fact may be wrong or something that's not proven an jus theory belief. I'm def buying faxon barrels. My only problem now is which round I wanna add to my beaUTIFUL Black Rain Ordinance that I have been upgrading since day 1 for the last 2 an a half years, also what length and profile. I only wished I made the money I used to climbing cell an broadcast towers, 28ft fall (not tower related) forced me on disability an I now get a month what I used to make in 4 frigging days. It's not gonna rob me my passion for firearms. Don't anyone reads this but helped decide between .300 or 6.5Grend or if u have another suggestion I'm all ears or eyes... whatever. Purpose? Coyote hunting at night. Have ATN and Sightmark day/night optics including the new 4K mini. But also I'd like to build a tactical upper with possibly a 11.5in to add a good can one day, but also not sure.300 or 5.56 . Sorry so long, watching these videos while finally replacing my gas block with the adj I got last year an I have NOTHING better to do... stay safe, keep your rounds down range and stay vigilant with these idiot shooters out firing on innocents cause they are tormenting these younger kids to act out these shootings to push 2A agenda. Our children an innocents should not be sacrificed to push ones agenda an beliefs that this country was founded on... God bless Eugene Stoner
Please, please discuss polygonal rifling and it's advantages or disadvantages
I would guess the 1 in 9 barrels being accurate or not with 77 grain 5.56 ammo comes to down to ammunition variance and barrel length. A relatively long barrel with a hot loaded round will have a higher muzzle velocity and therefore a higher exit RPM for the bullet. Conversely a shorter barrel and/or a lighter loaded round will have a lower muzzle velocity and may bring exit RPM low enough to make the bullet unstable in flight. Factory ammo can have as much as a 10% variance in velocity between rounds from the same box in the same gun.
In general a good video, but I have to wonder how you come to the conclusion towards thee 57:30 mark that 5.45 is a lower velocity round than the 5.56, given that out of a 16" barrel it's doing about the same speed (2900-3100) as a 5.56 does with a 20" barrel.
Excellent!!
The "infamous" cold-bore zero?
Consider the basic "hunting rifle".
Carried in all manner of climatic conditions and unlimbered to take ONE shot, if you are lucky.
NO "warming shots" into the back-stop, NO sighters!
ONE shot from a COLD bore to collect your hat-rack. Two, if you suffer from acute "buck-fever".
Before the hunt, do you spend half a day at the range, reeling off ten-round groups at 100 or 200 yds?
Or, do you fire a shot from a cleaned and DRIED barrel, have a nibble on the pastrami on rye, wait five minutes and fire a second shot and repeat for consistency, Adjust the scope IF necessary?
The wildlife is NOT going to idly lounge around as you reel off a couple of "warmers", a couple of sighters and then deliver the goods.. Most game species may be "colourblind", but they are not usually profoundly DEAF.
Some time ago, the interesting people behind "Ultra-Light Arms" turned out son purpose-built hunting rifles, "Pencil' barrels and super-rigid fibreglass stocks. They were built to make the first shot count. There is probably a bunch of information on their "philosophy" lurking around out there. NOT cheap rifles.
Military snipers are in the same boat, albeit with the added feature that the "game" (or one of his friends), may shoot back, with everything from a rifle to a mortar fire-mission. Most serious snipers operate in pairs, with the "Number Two" being an extra set of eyes and ears as well as being the "protection party"., and thus armed with something that is light, but which can lay down a modest field of 'disincentive" if required.
When you change the barrel do you change the gas block etc?
I built an A1 using a Faxon barrel with a 1/12 twist and cannot get it to stabilize any 55 grain bullets, (significant keyholeing). My next step is to try some 45 or 50 grain bullets, but can’t find any muzzle imperfections, and the rounds group fine with a vintage 601.
ty
Do you think you could ask him if he could film the button rifling process?