Just finished my first AR. I built the lower and purchased the complete upper. I first noticed that when I cycle the bolt, it would not close completely (just felt really tight). After a lot of cycling, it seemed to loosen up. I took it to the range today to put the first shots through it. When loading a round, the bolt will still not close. The forward assist does not help. When I pull on the charging handle to eject the round, it feels like something is physically wedged, as it takes both hands and a large grunt to eject the round. If I manually feed one round (no mag) and close the bolt, it closes completely about 8-9 out of 10 times. I was shooting some 5.56 bulk ammo I purchased. When I tried my buddies .223 ammo, it actually cycled through some. It still hung up, but not as often. The upper is a full LMT upper w/BCG and charging handle. I also swapped BCG's with my buddy and my bolt worked fine in his Bushmaster, his showed the same symptoms in mine. The ejected 5.56 rounds look like they are getting marked up by the barrel really good. Chrome lining a little thick? Something related to the BCG? Thanks for the help.