AR-180B bolt hold open device

This week we started on the bolt hold open device. These are the steps necessary to make this part.

This is how the part comes from the laser cutter. We leave the pivot hole small to allow us to ream it to size. We also add material to the pointed radius to all us to machine it to size as it is very easy for the tip to be burnt off during laser cutting.

DSC_5728csIt is set up in the machining center to machine these two parts.

DSC_5792csOnce out of the machining center we start the bending process. You can see the two reference point to allow a accurate and complete first bend.

DSC_5763csThey are bolted together so nothing moves out of place

DSC_5765csThe upper press fixture is put into place.

DSC_5769csThe first bend is pressed

DSC_5773csThe first press is complete and a second press will be performed to tighten up the bend radius and make the second bend.

DSC_5774csSet up for the second press

DSC_5776csNext fixture is added

DSC_5778csFinish pressing

DSC_5781csCompleted bolt hold open.

DSC_5784csStart and finish of the pressing

DSC_5787csOurs vs. the original

DSC_5786csFits the rifle like it was made to.

DSC_5789csAnother picture of it in the rifle.




13 comments to AR-180B bolt hold open device

  • Kerwin Kerr

    Will these AR-180B Bolt Stops work on the earlier AR-180’s?
    I have a Stirling AR-180 and I need a bolt stop for it.
    Kerwin Kerr

  • Chuck

    Kerwin: these bolt hold open stops will not work on an original AR-180.
    However with that said we are going to make a limited run of original bolt hold open stops.

  • Eric X Equis

    Would you consider making a replacement for the original AR18/180 that is modified to use standard AR15 followers? This way, a simple cut on the magazine body would be all that would be needed to get STANAG mags to fit/function in an AR18/180 AND allow more reliable anti-tilt followers (I prefer Magpul’s design) without the need to modify the rear of the follower; making them cease to function in STANAG rifles.
    Thanks and keep up the good work!

    • Chuck

      I will look into it.

      • Eric X Equis

        Hey Chuck, I kinda took a private poll with some fellow AR-180 (and one real AR-18) owning buds plus some input from over at the Bower’s boards and they ALL said they would buy a bolt catch that allowed unmolested STANAG followers.
        I’ve always considered this to be the one Achilles heel of the AR-18/180 platform… you can cut a simple slit in the mag body and the mag will still fit in an M4/M16/AR15 or other STANAG rifle but once you mod the follower to work in an AR18/180, you’re pretty much limited to that weapons platform (unless you reinstall a STANAG follower). Right now I have 5 mags specifically for my Sterling with another 8 or 10 “slitted” but running STANAG followers. They work but lock up with 1-round remaining in the mag. More an inconvenience but I’d rather feel that odd recoil and look to see an empty mag instead of that last hesitant cartridge hanging in there.
        If you DID make a bolt catch for the Costa/Sterling/Howa to use unmolested STANAG followers, I will be the first to prepay! Seriously. And I’m sure everyone with an original AR18/180 would do the same. Having interchangeable (well, with a slit in the side) mags with other STANAG rifles would eliminate the one gripe all us Armalite owners have on our rifles.
        If you DO decide to make this part, PLEASE keep me posted ( and if need be, I’ll prepay for this much desired and arguably needed part.
        BTW, know of anyone working in polymers? I have a revolutionary idea that will make a LOT of $$$ in the home defense and poor man’s tactical market. All I need is someone who can take my ideas and put em on a blueprint or program for a 3D printer!
        Think of a PEQ-15 for under $200! You game?

  • Travis

    I’d also would love a true bolt hold open for STANAG mags. I just got a Costa Mesa AR-180 and am struggling to get magazines modified properly and would love to use my PMAGS & others. If you do decide to make a run of them I would grab one in a heartbeat.

  • Dave

    Chuck, I am interested in replacement bolt hold open part for the original AR-180. I would be want at least 5 and depending on price perhaps as many as 10. I also would be interested in the same part to fit an unmolested standard AR-15 magazine, in the same quantities. If you R and D these parts and you are ready to make a run of them, I will be happy to prepay for them. Please keep my contact information so as to let me know when they are available.

  • RegT

    I would also purchase a bolt hold-open part that will work on stanag mags. I only located your site today, 01/02/2016.

  • RegT


    Sorry, forgot to add I have a Sterling, if that makes any difference.


  • Lionel Tatro

    I would like to be on the list for an original AR 180 bolt hold open assembly! My Sterling came without one

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