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.
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.
Chris
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.
Would you mind hitting these two bolts with calipers to measure the recess difference between main opening and also the plane on the bottom contact surface?
FA bolts are unicorns. Impossible to get. I’m looking into machinist and possible 3d print solutions.