• Win a RIX Storm S3 Thermal Imaging Scope!

    To enter, all you need to do is add an image of yourself at the range below!

    Join the contest

Third bolt release on AR-15

vinniedelpino

Major Hide Member
Full Member
Minuteman
  • Sep 27, 2020
    2,486
    5,019
    Charlotte NC
    I'm stumped. I'm on my third bolt release in two years and less than 5k rounds. Upper/lower are both billet spartan receivers from Joebob Outfitters. The bolt release inlet was a little tight initially, so i lightly filed until the part moved freely with no resistance (save for the spring) after I broke the first one. Both broken bolt releases were from Aero and the third that's going in now in Spikes. They're breaking right below the paddle.

    Any ideas? I'm definitely hard on the rifle, but there has to be something else going on here.
     
    I'm stumped. I'm on my third bolt release in two years and less than 5k rounds. Upper/lower are both billet spartan receivers from Joebob Outfitters. The bolt release inlet was a little tight initially, so i lightly filed until the part moved freely with no resistance (save for the spring) after I broke the first one. Both broken bolt releases were from Aero and the third that's going in now in Spikes. They're breaking right below the paddle.

    Any ideas? I'm definitely hard on the rifle, but there has to be something else going on here.

    When you say you "lightly filed" are you talking about the lower receiver or the bolt catch?

    What parts make up your bolt system? M16 , AR15, lighter or heavier bolt? What weight buffer and standard or custom spring?

    Are you running factory ammo or handloads? What bullet weights and velocity are you seeing?

    What I'm trying to determine is if the area filed caused a defect that may be contributing to the breakage.

    The other questions are related to the speed/force of the bolt into the bolt catch that could be causing the breaks.
     
    When you say you "lightly filed" are you talking about the lower receiver or the bolt catch?

    What parts make up your bolt system? M16 , AR15, lighter or heavier bolt? What weight buffer and standard or custom spring?

    Are you running factory ammo or handloads? What bullet weights and velocity are you seeing?

    What I'm trying to determine is if the area filed caused a defect that may be contributing to the breakage.

    The other questions are related to the speed/force of the bolt into the bolt catch that could be causing the breaks.
    I filed the lower receiver with a jewelers file. The bolt catch was in tact. I can't imagine I took more than a thousandth, maybe two. It was awfully tight beforehand.

    Toolcraft FA carrier, H buffer (I believe) and standard spring.

    It's a 300BLK, by the way. 90%+ of rounds through the rifle are 209gr hi-tek subs over a pinch of CFE-BLK. I'd have to check my load data as these things were loaded a while ago. They're definitely subsonic though.
     
    • Like
    Reactions: 4Mogger
    I filed the lower receiver with a jewelers file. The bolt catch was in tact. I can't imagine I took more than a thousandth, maybe two. It was awfully tight beforehand.

    Toolcraft FA carrier, H buffer (I believe) and standard spring.

    It's a 300BLK, by the way. 90%+ of rounds through the rifle are 209gr hi-tek subs over a pinch of CFE-BLK. I'd have to check my load data as these things were loaded a while ago. They're definitely subsonic though.

    Being sub sonic loads and standard components I can't see anything wrong. I know it is to late this go around but next time you need to modify a part, do it to the least expensive part in case a mistake is made. Cheaper to replace a bolt catch than go through the hassle of replacing the lower receiver.
     
    You might check the over travel on the cycling mass.... see how far your bolt is moving past the bolt catch when fully compressed into the buffer tube.
    You can't do this with the charging handle only, so.... lock the bolt back, then use a blunt stick to press the bolt face as far back as you can.

    IMPORTANT !!! Wear safety glasses... you don't want to launch your stick into you eye, since you depressing the bolt face will release the bolt catch.

    If memory serves me... you "want" 3/16 ish of an inch max over travel.

    Much more and the mass has enough oomph to smack the bolt catch pretty hard.

    FWIW... it is a common issue in AR PCC's, breaking bolt catches that is.
     
    I know it is to late this go around but next time you need to modify a part, do it to the least expensive part in case a mistake is made. Cheaper to replace a bolt catch than go through the hassle of replacing the lower receiver.
    Exactly. Gunsmithing 101. Always modify the least expensive OR more readily available part, first.
     
    • Like
    Reactions: camocorvette
    You might check the over travel on the cycling mass.... see how far your bolt is moving past the bolt catch when fully compressed into the buffer tube.
    You can't do this with the charging handle only, so.... lock the bolt back, then use a blunt stick to press the bolt face as far back as you can.

    IMPORTANT !!! Wear safety glasses... you don't want to launch your stick into you eye, since you depressing the bolt face will release the bolt catch.

    If memory serves me... you "want" 3/16 ish of an inch max over travel.

    Much more and the mass has enough oomph to smack the bolt catch pretty hard.

    FWIW... it is a common issue in AR PCC's, breaking bolt catches that is.
    I was waiting for someone to mention BCG length and/or travel! Good good.
     

    Attachments

    • Arise dead thread.png
      Arise dead thread.png
      461 KB · Views: 23
    Truth is, the bolt catch shouldn't break no matter how much you pay for a parts kit. Something might be putrid in Denmark if a lower keeps having a broken catch.

    Get the Forward controls latch and keep us posted. I only buy high end Geissele parts kits with Maritime latches any more, because I only buy high end lowers. But I don't beat my good rifles either. Maybe I should.
     
    Last edited:
    I'm stumped. I'm on my third bolt release in two years and less than 5k rounds. Upper/lower are both billet spartan receivers from Joebob Outfitters. The bolt release inlet was a little tight initially, so i lightly filed until the part moved freely with no resistance (save for the spring) after I broke the first one. Both broken bolt releases were from Aero and the third that's going in now in Spikes. They're breaking right below the paddle.

    Any ideas? I'm definitely hard on the rifle, but there has to be something else going on here.
    v seven bolt release is all I use on large frame gassers because it's the only one that hasn't broken yet!

    small frame get Colt or LMT
     
    I was waiting for someone to mention BCG length and/or travel! Good good.
    +2 on evaluating how much the BCG over-runs the bolt catch... If the BCG has too much over-run (IE gap between BCG face and bolt catch at its rearmost extent of travel), there is a very high chance to break them prematurely.

    This is an affliction that tends to affect any AR with a heavier reciprocating mass and a strong spring. These are typically PCC's and large frame AR's. I had it happen in a large frame AR.