CMMG 16.1″ Barrel Sub-Assembly .300 AAC Blackout

The CMMG Barrel Sub-Assembly is designed for use in a custom AR-15 upper. It is chambered for .300 AAC Blackout and features a carbine-length gas system with a medium taper contour. Finished in black nitride and constructed from 4140 chromoly steel, the assembly ships with a properly installed M4 barrel extension and is headspaced at the factory. The 1:7 rate of twist supports a broad range of .300 AAC Blackout projectiles.

Key Specifications

• The caliber is .300 AAC Blackout.
• The barrel length is 16.1 inches.
• The rate of twist is 1:7.
• The muzzle threads are 5/8-24.
• The finish is Black Nitride.
• The material is 4140 Chromoly Steel.
• The profile is a Medium Taper contour.
• The gas system length is Carbine.
• The contour designation is MT.
• The barrel includes a properly installed M4 barrel extension for headspacing.

Built for shooters assembling a dependable AR-15 upper, this CMMG sub-assembly pairs durable materials and common accessory threading with a versatile 16.1″ medium-taper profile. Its combination of black nitride corrosion resistance, 1:7 twist, and carbine gas length provides a practical balance of handling and performance for .300 AAC Blackout applications.