Ok. I put together an AR from parts, It is all RRA with the exception of a Bushmaster Barrel. I have only had the opportunity to shoot it twice. The types of ammunition that I had were wolf and some XM855, I think the PD stuff. Anyway, I loaded the magazine with a few rounds of the XM855 and closed the bolt. Fired the first round and the bolt didn't close all the way. I pulled the charging handle back and let it go again. It closed and I fired again. This time it cycled. Well, the problem that I had with cartridges not feeding continued with both kinds of ammuntion. Sometimes it was so bad, that I would have to pull and release the charging handle three or four times to get a cartridge into the chamber. Eventually it smoothed out for the most part as long as I downloaded the magazines (30 rounders, green followers, teflon from ammoman. Way too expensive looking back btw.) to less than 27 rounds. Today, I went to go try to really sight it in (didn't have a rest or enough space before) and I started out with a few magazines loaded with around 10 rds XM855 each. Never had a problem. Ran out of that and started using the wolf, and it wouldn't feed a single round. The bolt wouldn't even close on the first round without trying 3 or 4 times. Granted, this was with fully loaded magazines. I took out quite a few rounds and tried again. Same thing happened. There were some other guys there waiting to use the range, so I just got up and left. Plus it was really embarassing having something that you put together malfunction in front of a bunch of people. What do you guys think is the problem. The lips on the magazines seem kind of sharp; Could I file them down a little to smooth them out? Would it help if I bent the front of the feed lips up just a little to give a better feed angle, or would that interfere with something? Or is it just crappy ammunition? ( I hope not, I just bought 1000 rds of wolf 55gr, and I don't like to throw away money.) Anyway, If someone on here has had a similar experience and possibly a solution, some info sharing would be greatly appreciated.