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CMMG 9MM Barrel and Bolt Carrier Group (BCG) Kit - 8"


Out of stock

CMMG 9MM Barrel and Bolt Carrier Group (BCG) Kit - 8"

Special Price $399.99 Regular Price $474.95

The CMMG 8" 9mm 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, 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.

Their Barrel and Bolt Kits are designed to work exclusively with mil-spec AR-15 upper receivers with a modified ejection port, like their MkG/MkGs upper, and most mil-spec AR15 lowers when used with 9 AR Conversion mags as well as their MkGs Mk17 and Mk9* lowers. Other manufacturers’ receivers may work, but we cannot guarantee function or reliability.



  • 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
  • Finish: Nitride
  • Weight: 1.7 lbs.


*Older Mk9 lowers will require one of CMMG's retrofit kits to convert it to a Radial Delayed Blowback compatible lower, instead of Traditional Blowback.


All CMMG products come with their Lifetime Quality Guarantee.

More Information
SKU 99D517A
Product Type Barrel
Manufacturer CMMG
Thread Pitch 1/2x28
Twist Rate 1:10
Color Black
Finish Nitride
Platform AR-9
Barrel Length 8"
Caliber 9mm

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