I have a receiver set Im working on.
I just started assembly and the upper and lower fit it too tight
The only way i can get the pins in is to put the front one in first then close upper and drive the back one in with a punch
It will not go together by hand
Upper is Mur with a gen 2 noveske lower
I tried the upper on a different lower and it fit so I think it's the lower
Any suggestions to lossen it up enough to assembly and dissembly more easily ?

