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Rock River Ar15 Bolt failure


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  • Rock River Ar15 Bolt failure

    Has anyone ever seen a bolt sheared in half on an Ar15 or M16. We had a bolt seperate completely apart (while extracting a round) on the range last week. It seperated where the cam pin secures the bolt into the carrier, on the front half. I have looked around on the web and can find no other mentioning of such a thing. Our rifles are not very old and have a pretty low round count. We have not even had to start replacing extractors yet.

    Looks like there is some merit to MP testing after all.

  • #2
    I'd be curious to see pictures of the broken bolt. I have never heard of this happening.


    • #3
      it happens. that is one of the "weak" points on an ar bolt. when they fail, it is usually there or one of the teeth that break.


      • #4
        The only times I have had this happen in tens of thousands of rounds through M16s is with DPMS bolts.


        • #5
          Someone took the.bolt apart maybe leaving the pin out our not completely seated?

          «Army MP»


          • #6
            This is a known failure point. It's not common, but as nkpd44 pointed out, it's one of the areas. Depending on the round count, this is either unacceptable (low-to-higher round count) or not unreasonable (very high/extremely high round count).
            As part of our inspections, we do random magnaflux inspection during our annual inspections. We have 15 rifles currently in service in squad cars, and we do 3 per year. Never the same ones twice. It hasn't yielded any problems, but we also issue Colt.

            If it doesn't get replaced via warranty, I would suggest purchasing a BCM bolt as a replacement.

            Magnaflux test the rest of your bolts and cam pins. Degrease, then use a torch or heat gun to bleed and wipe the metal dry. Buy a UV pen and a black light and color the component with the pen. Then inspect in the dark under blacklight, using a handheld magnifying glass (borrow one from one of your CSI's) to look for fractures in the metal at the aforementioned weak points.

            Apply cleaner to the component when done, wipe clean, then reapply lube liberally.

            Addendum: if you find any sign of microfractures or other signs of concerning stress, IMMEDIATELY REPLACE the component. Do not continue to use the component for any reason. I know how agency command staff bean counters think, and they may pull some fvcked up shlt and say it's "not enough of a problem yet" to warrant replacement with an $80 component. If you have to, take a hammer to that bitch and break it and force them to have to replace it. Say that it fell or that Chuck Norris needed a toothpick or something.
            My agency has this habit, and I've seen several others. I carry a pliers at the range and break feed lips on any magazine that even slightly bent or cracked feed lips. If I don't, the mags will make their way into duty rifles. Once my agency learned that you can run an AR15 with one gas ring (and thus debunking that BS myth about staggering the gaps), they tried to stop me from replacing out of spec gas rings.
            If this is not an issue, disgregard.
            Last edited by Reedo; 08-15-2014, 01:56 AM.
            "Facts are stubborn things; and whatever may be our wishes, our inclinations, or the dictates of our passions, they cannot alter the state of facts and evidence."
            -John Adams

            Disclaimer: My statements are personal opinions, and in no way reflect those of my agency.


            • #7
              The armorer sent the whole rifle back to Rock River so I can't get a photo. Rock River apparently said it may have been caused by a shot out barrell. While is absurd either way we have not put that many rounds through the rifles so either the barrel sucked or the bolt sucked. Either is unacceptable. That said I am not the armorer and they ordered the non CL barrelled rifles so the chamber and barrell are going to suffer from accelerated wear. The standard metal GI magazines accompaning the rifles are just now having to be replaced for the first time to give an idea of the round count.

              The carrier and bolt were assembled normally, only the head portion with the lugs could not be retrieved from the chamber.


              • #8
                Can you upgrade to a higher quality rifle like Colt or BCM, for example?


                • #9
                  It is a department issue weapon. I don't have any say in anything but what type of sling I use on it. No personal long guns allowed.


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