The best on the bolt carrier groups. The top is definitely the common 5.56mm bolt carrier team. Detect the bolt, cam pin along with the carrier key. On the bottom is the 9mm SMG bolt team. The Colt SMG fires from a closed bolt, is provided that has a collapsible https://jaredpdioy.blazingblog.com/26635313/little-known-facts-about-colt-10-5-inch-9mm-smg-upper-receiver-assembly