I'm having issues getting my 7.62x39 AR to work with cast bullets. The mold I've been using is a LEE C312-155-2R. I am powder coating these boolits, and am also using a gas check. I am seating so that the OAL is 2.20".
I originally had them sized to 0.3125", but that was too fat. The bullet would get pulled out of the case and would just be left lodged in the barrel. So after knocking the bullet out of the barrel, I slugged the barrel and did a cast of the chamber. The barrel is at 0.311", and the throat is at 0.312". I figured sizing to 0.311" would let the rounds feed smoothly, but that didn't end up being the case. They definitely fed better, but I still had some rounds not chamber fully. After inspecting some of the rounds, I noticed that the powdercoat had been more or less shaved about 1/2 to 3/4 the length of the exposed part of the boolit. I measured this just to see what it said, and they ranged from 0.309" - 0.310".
At this point, I'm not sure what the problem is. Maybe I got the powder coat too thick towards the front half of the bullet? Maybe it's just too fat in general? I'm tempted to buy a different mold to see if that solves the problem, but I don't want to spend the money unless I have to. The one I was looking at is the 312-145 Elvis from Arsenal molds. I'm not sure if it would be any different though. Any suggestions?
http://arsenalmolds.com/index.php?ro...product_id=192