Maybe this fits in with my chandelier in an outhouse thread, but I can't tell the difference between tier one or tier 7. My first ar was a lite16, no modifications. I think it was a dpms. With very little load development it was a .5 moa rifle using berger 52 grain bullets. Since then, I used a bravo company blem upper thermo fitted to a bartlein 6.5 grendel barrel on top of an 80% lower, timney trigger. Again, I found berger bullets made it happy, it shot easily in the .3s on a good day. I always knew before I sat down at the bench if it was or wasn't going to be a good day.
My focus has always been accuracy, so I can't speak to reliability during rapid fire. Fourty rounds in a day is a lot of shooting for me. I have had guys who were amazed that an 80 lower could shoot that well. (Guys who actually witnessed the groups being fired)
I'm convinced proper assembly with a quality barrel and a good trigger, coupled with load development is more important than the name brand on the lower. I favor bravo company uppers because they're slightly undersized and give a nice tight fit to the barrel extension when you freeze the barrel and lightly heat the upper.
My focus has always been accuracy, so I can't speak to reliability during rapid fire. Fourty rounds in a day is a lot of shooting for me. I have had guys who were amazed that an 80 lower could shoot that well. (Guys who actually witnessed the groups being fired)
I'm convinced proper assembly with a quality barrel and a good trigger, coupled with load development is more important than the name brand on the lower. I favor bravo company uppers because they're slightly undersized and give a nice tight fit to the barrel extension when you freeze the barrel and lightly heat the upper.