The AR57 select fire debacle…

I love the idea of the 5.7, so it was all to natural to end up with a five-seven upper for my AR. When I tried that on my select fire receiver, I instantly fell into sad panda mood… Turns out the bolt carrier group provided is semi auto ONLY. Since its a special BCG, replacements were needed.

Just a pic of the two side by side shows there is not much difference, but enough to kill the giggle switch.

About the author

I'm old, and I've been shooting and reloading since I was about 7. I started depriming and sizing brass for my father with a RCBS rock chucker press (which I still have) have now primarily use a Dillon 1050, and several Dillon 550b(s) I have been a shooter/member of IDPA and IPSC, though I'm not current, and I have not been to a competition in quite some time. Lately I've been into shot shell reloading, and trap shooting.

2 throughts on "The AR57 select fire debacle…"

  1. Hey Rob. Stumbled across your page. Looking for info on
    A AR57 Full Auto bolt. Specifically how to tell which bolt in your post picture is FA configured. I bought a used 57 Gen 1 upper and I dont know what I have.
    Any guidance would be greatly appreciated.
    Thanks in advance.


    1. To get a F/A bolt that will trip the auto sear, Someone would have had to send in SOT/copy of MG registration and buy the specific bolt. As far as I know, none were shipped FA capable. Seems like there is a FA stamp on the end of the bolt. I’ll take pics of the end when I get back to the parts.

Leave a Reply

Your email address will not be published. Required fields are marked *

This site uses Akismet to reduce spam. Learn how your comment data is processed.