Ever Wondered What 80-100K Rounds Fired Does To An AR-15 Barrel?

Chamber cut away

Talking with my friend Matt over at Noveske, he told me about some science that he recently conducted that was far too cool not to share with all of you. After I had got his blessing, he sent over some photos of a barrel that was sent back to Noveske for some reason after putting anywhere between 80,000 to 100,000 rounds downrange. The results are nothing short of awesome.

The three barrels are all impressive, but the one with the sight post is caught my attention most. The other two are stainless barrels with an estimated 30 to 40 thousand rounds fired, one of them was still shooting reasonably well as I understand it. It sounds pretty hard to believe that barrels that worn out will still shoot 3 MOAish groups, putting it on par with some of the more inaccurate guns we have tested at TFB.

You can see below that there is near nor rifling left in the chrome hammer forged barrel and the gas port has near eroded all the way through the barrel. Matt said that this barrel was grouping in the area of 18″ at 35 yards or so, he wasn’t able to tell me who in the hell continues to use a barrel that far past the service life. The only reason I could come up with is some machine gun rental place in Vegas.

shot out barrel gas port Three barrel cut away

Hat tip to Matt at Noveske, thanks buddy!



Patrick R

Patrick is a Senior Writer for The Firearm Blog and works in the shooting sports industry. He is an avid recreational shooter and a verified gun nerd. With a lifelong passion for shooting, he has a love for all types of firearms, especially handguns and the AR-15 platform. Patrick may be contacted at tfbpatrick@gmail.com.

The above post is my opinion and does not reflect the views of any company or organization.


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  • Anonymoose

    So clean and smooth~

    • PK

      Does anyone else want to load tiny little 5.56x45mm shotshells now?

      • Dr. Longfellow Buchenrad

        I wonder if you could shoot it out to the point of needing an NFA stamp for having a 16″ SBS. Im sure the ATF would figure something out.

        • Sunshine_Shooter

          Since they’ll prosecute for a trigger breaking from wear and accidentally doing small bursts, yes.

    • Baggy270

      Needs some Aqua Velva!

  • >> Matt said that this barrel was grouping in the area of 18″ at 35 yards or so, he wasn’t able to tell me who in the hell continues to use a barrel that far past the service life.

    Shoot a few rifles used for Army BCT and cleaned in the manner prescribed by the drill sergeants there and you’ll have your answer…

    • PK

      No, it’s supposed to make that sound when being cleaned, right? Like a woodsaw?

    • 11b

      I specifically remember drenching my SAW in break cleaner, then taking it in the shower for a scrub down with hot soapy water. Of course it still wasn’t clean enough for Big Drill. Then they announced there was an ultrasonic parts cleaner in the arms room, but we weren’t allowed to use it.

      • Phillip Cooper

        Similar here, but we used brake cleaner.
        Is break cleaner used to clean up after a leisurely nap in the sun?
        (I kid, chill out… 😉 )

        • M.M.D.C.

          Give the guy a brake.

  • Matt

    I am curious to see how the case ejection patterns changed with the erosion in the gas port…

    • noob

      I am curious to know how big a malfunction it is when the gas port finally cuts all the way through and flames/flying metal chunks start coming out.

      • PK

        Big-ish, at least.

      • iksnilol

        Just drill new gas port and move the gas block a bit back (and shorten the gas tube appropriately).

  • Ron

    The US military specified service life for a rifle (now carbine) barrel is significantly lower than that, The Marine IAR requirements was a little over 3x the life expectancy of the standard M16 Family of Weapons requirement and it was only 20K rounds at that.

    • PK

      The military still expects rifles to be able to hit people past bad-breath distance. Whoever owned these barrels obviously didn’t care about terminal effect or accuracy, but whatever caused that sort of wear far past the service life… I bet it involved a lot of mag dumps.

      • Phillip Cooper

        Mag dumps by inbred mouth-breathers. Likely in a place which shares its name with a whiskey….
        the two are likely more connected, still.

        • Norm Glitz

          Not too bigoted, are we?

          • Phillip Cooper

            I live around them. I can say this. It’s not bigotry, it’s situational awareness.

          • Norm Glitz

            Two very different things. They way you expressed it was classic bigotry.

  • Chris

    I would argue BCT rifles do not actually get fired as much as many think. A rifle may be used by five cycles of recruits in a given year, less so if talking about OSUT recruits (around a four-month cycle). In each cycle, the recruit will group and zero on a day. Let’s say he or she is horrible, and it takes 40 rounds to do so. Army qualification requires 40 rounds, so let’s once again say that the recruit in question is terrible with a rifle, so 80 rounds, in order to qualify on the second attempt. That’s 120 per cycle, times five cycles, so 600 rounds per year. Not that much. There are also variables such as the rifle being turned in for 3-level maintenance, or it’s recruit owner being dropped or recycled from training which will decrease rounds put through it in that year. That rifle, in 30 years of service, will sustain 18,000 rounds through the barrel.
    There are definitely units and schools that go through much more ammo on a single gun in a year. I’m sure the 18B course at Bragg sees constant barrel replacements on their M4A1s, even with the heavy barrels.
    I’d put money on those guns coming from a certain indoor gun range in Nevada, which does a great job of documenting their weapons use.

    • Ron

      Non-infantry OSUT recruits fire 500 rounds during their time in basic training, Infantry OSUT recruits fire 730 rounds during their basic training.

      • 11b

        Maybe according to TRADOC but not in practice. I was in infantry OSUT and I can tell you we fired nowhere near 730 rounds. I’d estimate we went through a full combat load of 210 rounds, tops, and that was 8 years ago pre budget cuts. Most ’rounds fired’ are blanks.

        • Ron

          If the drill sgts follow the POI recruits are suppose to fire 310 rounds (370 for OSUT) for basic rifle training and 190 rounds (360 for OSUT) for advance rifle training.

          The Marines fire 800 rounds for non-infantry Marines between Boot Camp and MCT and 1264 rounds for infantry Marines between Boot Camp and ITB.

          All those number exclude blanks, crew served weapons and SAW training.

        • Chris

          Roger, I thought it was clear I was speaking on ball ammo/M855[A1] only. Blanks are fired plenty in BTC, but do not significantly contribute to the wear of the barrel.

          • Well, let’s examine that statement for a second. True, there’s no projectile to wear down the rifling. But I would presume you’d see gas port erosion and maybe some wear on the chamber (possibly throat erosion?).

          • Blaine

            I kind of doubt it. Blanks are pretty weak and I just couldn’t see them eroding the gas port significantly. Definitely not enough to damage the chamber.

        • jamesone

          I was a non combat mos basic in 2007 Army. Let’s see. 60 rounds qualification. 60-90 fire/cover fire, movement. 90 convoy live fire. 120 night fire. So 300-360. Some shot a lot more due to not qualifying and doing it 2-4 times or even having to re zero. So yeah would agree they don’t stick to the tridoc req.

    • DIR911911 .

      you must be thinking of Air Force basic training , I know we fired a lot more than that in Army basic in the late 80’s.

      • buzzman1

        Not at Jackson or Leonardwood. Well less than 2oo rounds.

    • Gambler X

      That is exactly where I was thinking they might have come from.

  • Jerry_In_Detroit

    Was it Hatcher or Mann who once substituted a patch of rough sandpaper on a rifling machine and found the spiral scratches were sufficient to stabilize the bullet?

    • iksnilol

      So I can just sandpaper the inisde of a smoothbore to get some stabilization?

      • Hokum

        Yes, but only if you’re Hatcher or Mann…

        • iksnilol

          Well, I do have an Y chromosome… so I guess I am a Man.

      • PK

        If you can do it in a decently steady twist, yes. It just doesn’t last very long.

  • DanGoodShot

    That just the new 223 smooth bore for countries that only allow shotguns. Duh.

    • PK

      We’re going to need really tiny clays.

      • JustAHologram

        There are some 40mm clays

      • Phillip Cooper

        With an 18″ pattern at 35 yards, I think you’d need HUGE clays.

        • PK

          That will make it even easier to hit with 5.56x45mm shotshells! Tiny clays are needed.

      • Mark Are Reynolds Ⓥ

        No, UFO sized clays..

  • Phillip Cooper

    Very interesting pics!

  • alex waits

    More of these articles please. 😛

  • Phillip Cooper

    And that, kids, is called “keyholing”….

  • Sunshine_Shooter

    Why hit the enemy with a .22 inch wide projectile when you can hit them with a .50+ inch long projectile?

  • jpcmt

    So what was the big science thing Matt discovered other than worn out barrels? Also, what are we looking at in the pics besides what appears to be some or total worn grooves and a worn gas port?

  • Ron

    At least in the Marine Corps, outside of recruiting training, weapons cleaning is not the same old white glove affair as it use to be.

    • Wow!

      Sometimes I even wonder why we clean guns aside from precision shooting. It seems to be an old standby from the days of corrosive chemicals formulations. I mean, shooting a pack of wolf through my rifles leaves my bore shiny clean. Really the only thing we need to do is to lube. And maybe clean only once every several thousand rounds (or if it was exposed to a lot of dirt and mud, in which case I just hose it with a garden hose, blow air, lube and call it done.

      • FrenchieGunner

        Actually in precision shooting you must not clean your barrel before it is needed (excessive fouling, dirt or sand…).
        in the USMC, the cleaning regime is so high because it’s the how it is, marines were exposed to highly adverse environmental conditions (salt water, high humidity…) so it stayed.

        • Wow!

          You must not clean your precision gun of copper. The powder fouling should be cleared out as much as possible which does attract some moisture (although even then, the groups are pretty good even with power fouling left in, but they are better with it cleared out). This is why I use Eds red for all of my cleaning, and a small bottle of hoppes every couple thousand rounds on the precision rifles.

          The military only has one cleaning solution because it simplifies logistics and really the difference in performance is negligible since at the distance that the fouling makes a difference in shot placement, the target is generally too far away to get a positive ID or respond accurately, so volume of fire when confirmation is made is possible.

  • Christian Hedegaard-Schou

    Is this what Joe Biden meant when he was encouraging everyone to just get a shotgun?

  • nova3930

    Always wanted an AR-15 smoothbore musket….

    • VanDiemensLand

      Proof what? I hope not, it’d be scary to think two sets of eyes were responsible…

      • JSmath

        You said as you replied to the wrong comment.

        • VanDiemensLand

          Hahaha lucky this isn’t my job 😉

  • Joe Buck

    Does nobody proofread these articles for grammar?

  • That photo is givin’ me the skin-crawlin’ heebie jeebies.

    • You think that scares you? the replacement NOS barrel was $5K for the Stoner 63a

      • ( ⊙_⊙)

      • Geoff Timm

        Wow! Would relining have helped? Geoff Who is stunned

        • Not usually a good idea on machine gun barrels. I did use the parts from the original and had an excellent gunsmith rebarrel with it but original barrels are still extremely expensive.

          • Wow!

            I almost gaurentee you can just buy a lathe and turn a new barrel from a blank at lower cost.

          • jcitizen

            What! And ruin the $65,000 dollar value of an original Stoner 63 system?

          • Wow!

            I’m pretty sure he is doing the same amount of damage by shooting the barrel rifling clean off. Guns are meant to be shot, and if they are collectables, they belong in a museum. This isn’t a bubbaed spray paint, spot weld rails all over kind of deal. It is just re-barreling. A simple and common type of maintenance on any firearm.

          • jcitizen

            I shoot a lot of rounds out of collectible firearms, so I agree with you there. Fortunately it is easy to re-barrel an AR. I don’t know how many times my friends have had to replace their Remington 788 rifle barrels because of all the shooting at prairie dogs. It is well worth it!

          • Doom

            Why would having a qualified gunsmith making and installing a high quality barrel destroy the value? Id just have 5 or so new barrels made for the price of the one original, then have an original sitting around to slap onto it if you did have to sell it.

          • jcitizen

            Sound like the plan to me. It would be challenging to make a new removable barrel with all fittings for a Stoner though.

      • Adam

        WTF!! $5 k for a barrel??????? Was it gold plated and diamond encrusted?

        • Mike Lashewitz

          Beats the $18 K couch on the USS Ticonderoga or the $500 toilet seats…

          • AK™

            cheap compared to what the alphabet letter spy agencies spend..

        • Nobody Inparticular

          > Stoner 63A

      • Mark Are Reynolds Ⓥ

        and of course paid for with Federal Reserve notes created out of thin air which is the main reason the gooberment can afford most of the over priced crap they buy.

  • ClintTorres

    Fleet Yaw.

  • mig1nc

    Looking at the erosion pattern on that gas port, I wonder if the angled gas port used by Triarc would not have looked like that. I mean, other than obviously not being 90 degrees.

  • B

    SOF! Duh tards

  • Aimon Bustardo

    Holy keyhole Batman!

  • Mike Lashewitz

    I am sure glad I will never have this kind of failure. I cannot afford the ammo to make that happen. Wish I could. . . .

  • Andrew Foss

    s/well/well,
    s/near/nearly
    s/MOAish/MOA-ish
    s/is some/would potentially be a
    :wq!
    And the title: “This is what more than eighty thousand rounds worth of barrel wear looks like.” Question marks in an article title are a sign of clickbait. Avoid.

  • B. Young

    makes me think why someone hasn’t made a “keyhole” lever next to the semi/full auto lever…

  • Al Shartpants

    That is exactly what my targets looked like when I tried a box of Aquila .22 Sniper Subsonic ammo.

  • Lonnie

    skeet shooting in Texas!

  • billyoblivion

    I think I shot one when qualifying in the Air Force in the mid 2000s.

    It was an A1.

    • RA

      I thought that was a Steak sauce ;-D

      • billyoblivion

        If it was Steak Sauce I would written “It was A1”, however I wrote “It was an A1” indicating the M16-A1 model.

        Now let us all get out our copy of Strunk and White and…

        • RA

          Now that was really funny! Touch’e

  • The Brigadier

    Most barrels on high powered rifles need replacing between 10,000 and 12,000 rounds. The receivers on average for 7.62X51 rifles last an average of 70,000 rounds. It appears that .223 machine gun is no longer a collectible, but a beater. Re-barrel it and enjoy it until the receiver is on the verge of failing and then mount it permanently on your wall.

  • Blaine

    You’re spot on. I can’t tell you how many weapons I’ve seen cleaned with baby wipes and soap. Leaders are obsessive about “cleanliness” when the only factor that actually matters is lubrication.