With the introduction of USPSA PCC, I'm in the market to build a 9mm AR.
Do they use regular 5.56 AR free float rails?
I see there's a 9mm buffer, I'd it necessary over a carbine or H1?
Which is better, Colt SMG or Glock lowers? As far as reliability in feeding goes.
Can I use a standard stripped upper I have laying around?