| Caliber | 9mm |
| Operating System | Radial Delayed Blowback |
| Barrel Length | 8 |
| Barrel Twist | 1:10 |
| Barrel Contour | MT |
| Barrel Material | 4140CM |
| Barrel Twist | 1:10 |
| Muzzle Thread | 1/2 X 28 |
| Gas Port Location | N/A |
| Gas Block | N/A |
| Finish | SBN |
| Weight | 1.7 |
AR Parts Notice - State/local restrictions may apply in CT, DC, IL, MA, NJ, NY, or WA. Customers must review our Shipping Policy prior to ordering.
Barrel and BCG Kit, 8" 4140CM, SBN, 9mm
Our 8" 9mm Barrel and BCG Kit allow you to build a Pistol Caliber Carbine using our Patent Pending Radial Delayed Blowback System™. Unlike typical direct blowback systems, Radial Delayed Blowback 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.
Our Barrel and Bolt Kits are designed to work exclusively with mil-spec AR-15 upper receivers with a modified ejection port, like our Mk4 upper, and most mil-spec AR15 lowers when used with 9 AR Conversion mags as well as our MkGs Mk17 and Mk9* lowers. Other manufacturers’ receivers may work, but we cannot guarantee function or reliability.
*Older Mk9 lowers will require one of our retrofit kits to convert it to a Radial Delayed Blowback compatible lower, instead of Traditional Blowback.
All CMMG products come with our Lifetime Quality Guarantee.