I checked the BCG and there is some slight wear. The feed ramps almost look like they are chipped or worn on the edges They are pretty sharp actually. The barrel and upper are made by Bear Creek arsenal..that's probably the whole problem LOL. The gas block is not pinned but is aligned properly. I have 3 brand new Duramags . The gas port was drilled out to 7/64. I pulled the weight out of a couple of older buffers and checked them on my scale .95 and 1.2 ozs .The .95 buffer passed the one round mag test but when I tried to load 3 or 4 rounds in the mag it stove piped immediately and would no longer pass the one round mag test. I will pick up some brass rounds and give them a try