well, tore it apart and the gas port seems to be fine, It looks kinda big to me but what do I know. The BCG is practically new an the gas key is tight and staked. Because the BCG group is newer I'm thinking there may be a bit of drag on the gas rings till they get more wore in but that shouldn't keep it from cycling. The gas tube is clear and appears to be fine. The hole in the barrel matches up to the hole in the front sight assembly. Put the upper on an A2 style lower and it seemed to work better but not much. It had a hard time working through the first five or so rounds in a thirty round magazine then it would run fine. I was running it dry also to see how it did in that condition. I'm not overly enthusiastic about a finicky rifle that has to kept soppin wet to run right. Polished up the bottom of the bolt carrier and the hammer so they should slide better. I'm gonna have to lube it and see how it works. I've never had an AR that refused to run (and ive had about a dozen or so) dry so maybe this is just a first. By the way, It did this with both XM193 and commercial Remington .223.
Would cutting a few coils off the buffer spring help? It was cycling far enough back to eject the empty but wasn't striping the next round out of the magazine.
This one is gonna be a problem child.