CCI AR Tactical which is the ammo that was causing issue measured .990 with variation of .002 + or -.
Federal Champion 36gr copper hollow point measured .975 with similar variation as CCI.
So until I get a few thousand rounds thru the mags or get motivated enough to polish interior of mags I will check and run ammo that measures close to the Fed Champ.
If you're unarmed, you are a victim.