So how much upper slop do you consider acceptable? I got a Stag upper yesterday and put it on my S&W lower and there is a small amount of play between the upper and lower, but not any daylight between them. The rear pin is pretty easy to push out.I have the same lower with a RRA on top of it and it is so tight that I cannot get the pins out with my bare hands.
That is fine. The AR was meant to have some play in it.
C4
Normal, I have some play in my Stag too. And the pins are easy to push out. I actually prefer this than having to use a pen or something to take it out.