If you insert a round into the chamber with the upper separate and no bcg in, how far should the round insert itself into the chamber. Also, should the round freely fall out if you hold the upper vertical or should it stay in the chamber? I've had an issue with my ar not feeding properly and I'm stumped. The gas tube/port are lined up right, the gas key slides over the gas tube without grinding or rubbing, and I have the proper buffer, yet I'm still having trouble. Sometimes it will shoot 4 rounds and then The bolt fails to travel back far enough to strip the next round. Sometimes the round wont eject. I'm wondering of maybe the cases are fitting too tight in the chamber? It's an ar stoner barrel and apparently people have problems with the cases getting stuck. I haven't had any get stuck (except one steel case) but I'm not sure what else my problem may be. I checked the gas rings as well and they're all good.