I have a fairly newly put together AR build, that started from a stripped lower that I had filled in. It's an Anderson Lower, with an A2 Buttstock and a 20 inch government profile 5.56 Upper with a 1:9 Twist. I have less than 200 rounds through this upper.
I first had an issue of light primer strikes, but that was fixed easily by getting an extra power trigger spring.
Most likely this next issue was unable to be seen due to my previous issues, or I had not noticed the problem before, but I now can try and diagnose this other problem.
I am having a lot of trouble getting the first round of a 20 or 30 round magazine chambered in my rifle. The 30 rounder is an Okay Industries magazine, and the 20 rounder is an unknown aluminum magazine. I have Pmags but from my previous experience, I believe that they had the same issues too.
Usually I lock the bolt back and let it ride, but even that gives it a fight. The first cartridge fails to get into battery, leaving the rounded lip on the side of the BCG visible. Extraction then needs to be quite forceful, to get the partially in battery case out of the chamber.
This same issue continues often for the second round in the magazine, but after that point chambering and firing the next rounds is completely smooth and painless.
Any idea on what may be going on in there? When I had inspected my BCG, there was some brass debris from the manufacturer that was likely left from testing, but otherwise I don't think there's anything dangerous going on in there. My suspicion is that I've left the chamber a little grimy or the BCG less lubed than it really should.
Can any of you provide some insights into how I can solve this problem? Under-loading my magazines would likely help but that doesn't seem to be the right thing to leave a problem unsolved.