Popgunshooter

I was sighting in my little .243 CVA single shot at the local range a few days back and the guy next to me had a fancy (don't know brand) AR15 type .308 and was all over the place on the target. As he shot he kept going farther and farther right until his military rear open sight adjustment was all the way to the left. I asked him if he was squeezing the trigger and he said normally he was a good shot. His barrel was extremely hot and I think he actually warped it from shooting so much.

My thoughts (former metallurgist for a transmission company) was with a military type rifle that would be used in combat the barrel should be properly stress relieved after rough gun drilling and machining so that when it got hot in combat it would not later stress relieve (bend) during shooting. I think this guy bought a lemon.

Comments?

mrbb

I highly doubt the barrel warped, I used, shot and sold thousands of these things, as well as used a lot in full auto(actually did a drill to see how many rounds on full auto it took to MELT a barrel to make it bend in full auto mode)

I have never seen anyone warp a barrel, I have however seen many guys shoot the rifling out of barrels shooting them too hot in a LOT of fast reloads and long non stop firing (more so in full auto's)
IMO< I will guess, it might just be the shooter, NOT all AR's of the same quality on trigger pull, making some folks that normally shoot better shoot worse!

and like all things, all the more so with SO many company's making and selling AR type rifle parts, and folks BUILDING and mix matching parts, its not that un common for things to be OFF a LOT, pending production runs, quality of part period, and who put things together!

way too many variable's here to Claim a warped barrel IMO

BUT anything can be possible too I am sure
just its a VERY low odds deal IMO!
been in the shooting game a LONG time!

Valorius

It would be next to impossible to warp the barrel on a semi automatic firearm.

Barrel nut is not properly torqued would be my bet.

Popgunshooter

Well, my company used to make transmissions and for the shafts used in them they use the same 4140 steel gun barrels are usually made from and drilled the long holes in them using gun drills just like the rifle manufacturers. We brought the bar stock in quenched and tempered to HRC 32-36 and did the drilling and machining to sizes which allowed finish machining. This is because when you do heavy machining to a material in the previously stated hardness range it puts in extreme stresses which when exposed to later high temps can be relieved and cause warping of these products. That's why after rough turning this steel it is usually "stress relieved" at 1000° F before final machining (much less stock removal which doesn't cause stresses). And of course the young, hot shot managers would try to save the cost of this stress relieving operation with disastress results. Believe me I've seen huge heavy duty transmission shafts warp so why wouldn't a gun barrel (much smaller diameter) not warp if it was not stress relieved during production?

I guess all I'm saying is that maybe a lot of barrels for these things were not made correctly. You guys could be right too (barrel nut). I mean to see a fancy rear sight adjusted all the way to the left side and the gun shooting a foot to the right.. I thought it was this guy so let him shoot one out of my little gun after I got it dialed in and he put one in the center with it.

mrbb

well as I said, anything is possible, , but I have never seen it happen in a rifle barrel(personally friends with a few rifle barrel company owners too that have sold hundred of thousands of barrels)
its just the liability side of firearms that I also think its not going to happen, fear of law suits, , so the barrel makers are doing what is needed to prevent things of this nature IMO!

there are many things that can cause issue

from sights on barrel being off center(much more likely)
could be a burn in rifling near end of barre, or bad crown on bore?l (again rather common, )

or say,a flash hider.recoil brake, being off center and causing a slight touch on bullet(seen this happen before, as not all rifle barrels are perfectly round to center of bore, seen many of them be off , so when your screwing things onto end of barrels, it can cause issue's possibly

and again a heavy trigger pull, and shooting to the right with a right handed shooter is Rather common as well!, there PULLING the gun to the right when firing!
when they shoot your gun, maybe a better trigger, and hitting where aiming, has NO real value on what the cause for the AR shooting poorly!, doesn;t rule out shooter that's for sure, as your comparing two different tools
would have been better having YOU shoot HIS gun, than him shooting your gun that has NO issue's?

as I said there are many reason things can be off, but I would place a warped barrel at the low low end of possible issue's!

when trying to fix accuracy problems, there are many steps one can take to try and resolve, and you will NOT be starting at possible cause being a warped barrel, IMO

Nomercy448

In the last 20 years, I have built, rebuilt, or otherwise serviced and test-fired somewhere around 750 AR-15 and LFAR rifles and uppers.

I have seen bent barrels, as indicated on the exterior of the barrel.

I have seen drifting bores which effectively equated to a bent bore, confirmed with dip rod.

I have seen barrels loose in the upper extension which shifted with recoil.

I have seen poor stress-relief which walked when the barrel warmed up, and back as it cooled.

I have seen ~750 barrels which could be bedded, thermally interfered, lapped, or shimmed and properly torqued to deliver reliable and repeatable accuracy on target, most of which delivering less than 1.5moa.

I have never seen a semiautomatic AR barrel shot hot enough to irreversibly warp the barrel.

Valorius

If he has his front sight mounted on the handguard it is entirely possible that it is shifting from recoil. Many handguards are not sturdy enough for a front sight to reliably hold zero. This could easily cause the problem described in the original post.