A SECRET WEAPON FOR COLT 9MM UPPER

The top with the bolt provider groups. The top is the standard 5.56mm bolt provider group. Recognize the bolt, cam pin and the carrier crucial. On The underside is definitely the 9mm SMG bolt group.Anything shorter than the usual 16-inch barrel is considered to be a brief barrel rifle, or SBR besides For those who have a stabilizing pistol brace.Ba