Build Your Own 9mm Pistol Caliber Carbine with Some Help from CMMG

This 9mm barrel and bolt carrier group from CMMG allows you to build a Pistol Caliber Carbine using CMMG's Patent Pending Radial Delayed Blowback System. Unlike typical direct blowback systems, their RDB technology uses a bolt that is forced to rotate and unlock, slowing the BCG. This results in a lighter BCG for a lighter firearm, and less felt recoil than a straight blowback system. All NFA rules apply.

CMMG Barrel and Bolt Carrier Group Specifications and Features:

• CMMG Item Number: 99D17C3
• AR-15 Barrel and Bolt Carrier Group
• Caliber: 9mm Luger
• Radial Delayed Blowback Operated
• 5" Medium Taper Barrel
• Twist Rate: 1:16
• Barrel Material 4140 Chrome Moly Steel
• Muzzle Thread: 1/2x28
• Salt Bath Nitride Finish
• Weight 1.4 lbs

Fits:

• Mil-Spec AR-15 Upper Receivers with Modified Ejection Port (like CMMG MkG/MkGs Uppers)
• Most Mil-Spec AR-15 Lower Receivers (When Used with 9 AR Conversion Magazines)
• CMMG MkGs Mk17 and Mk9 Lower Receivers

Note:
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. Other manufacturers' receivers may work, but we cannot confirm function or reliability.