Brownells 75th Anniversary - A Shooting Heritage
Menu

The CMMG MkG 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 CMMG 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.
While the CMMG GUARD 45 was designed for .45 ACP, they have tested it, and are proud to say that it is safety rated to fire 450 SMC.
The MkG Barrel and Bolt Kits are designed to work exclusively with CMMG’s MkG Lowers, and a mil-spec upper receiver with an enlarged ejection port. Other manufacturers’ receivers may work, but CMMG cannot guarantee function or reliability.

  • Radial Delayed Blowback Bolt (Patent Pending)
  • Requires enlarged ejection port for reliable operation
  • Chambered in .45ACP
  • Available in 5” or 8” lengths
  • Medium Taper Contour
  • .578x28 threads
  • 1-16 Barrel Twist
  • Salt Bath Nitride Finish

CMMG - BARREL AND BOLT CARRIER GROUP KITS 45ACP

narrow your choices »
Show Filters
2 Item(s)
Online Only
In Stock

Cartridge: 45 Auto (ACP)

Length: 8"

Contour: MT

Finish: Stainless Black Nitride

Muzzle Threads: .578-28

Twist: 1-16

Online Only
In Stock

Cartridge: 45 Auto (ACP)

Length: 5"

Contour: MT

Finish: Stainless Black Nitride

Muzzle Threads: .578-28

Twist: 1-16