The CMMG MkG GUARD Barrel and BCG Kit allow you to build a Pistol Caliber Carbine using their Patent Pending Radial Delayed Blowback System. Unlike typical direct blowback systems, the RDB uses a bolt that is forced to rotate and unlock, slowing the BCG. This results in a lighter BCG for a lighter rifle, and less felt recoil than a straight blowback system. The MkG GUARD Barrel and Bolt Kits are designed to work exclusively with the CMMG MkG GUARD Lowers, and a mil-spec upper receiver with enlarged ejection port. Other manufacturers' receivers may work, but we cannot guarantee function or reliability. 16a ^2 Medium Taper 1:10 Twist 4140 Chrome M Mfg: Cmmg
