Just tossing this out there, could this be a lube issue, action not operating smoothly?
Gun is drier than phuu.uck?
Just got my first AR and have never messed w em but from my understanding they prefer to run wet.
Not likely. That NIB BCG he has is pretty slick. I could run mine pretty dry and it ran like a sewing machine.. Hopefully when he tries his known good lowers all problems will go away. If that is the case, then I'd look at Trigger spring in backwards etc..
