The CMMG 22 ARC 20-inch AR-15 barrel (brand part no. 28D840C) is a barrel sub-assembly for shooters who want the ballistics of the .22 ARC cartridge on the AR-15 platform. CMMG machines it from 4140CM steel with a nitride finish and cuts a 1-in-7 twist to stabilize the heaviest common 22 ARC bullet weights. A medium (MT) contour balances weight with heat capacity, and a rifle-length gas system and standard 1/2×28 threaded muzzle round out the package. It suits a flat-shooting 22 ARC upper build.

Key Specifications

• Chambering is .22 ARC, a cartridge built for heavier .22-caliber bullets.
• Barrel length is 20 inches.
• The gas system is rifle length.
• Twist rate is 1-in-7, which stabilizes the heaviest common 22 ARC bullets.
• The contour is medium (MT), balancing weight with heat capacity.
• The steel is 4140CM, a tough barrel steel.
• The finish is nitride for corrosion resistance.
• The muzzle is threaded 1/2×28 for standard .22-caliber muzzle devices.

Frequently Asked Questions

What is 22 ARC? It is a next-generation .22-caliber cartridge built for the AR-15 platform, designed to stabilize heavier, higher-BC bullets than .223 or 5.56.

What twist rate does this barrel use? A 1-in-7 twist, matched to heavier 22 ARC bullet weights.

What thread is on the muzzle? A standard 1/2×28 thread that accepts common .22-caliber muzzle devices.

Buy the CMMG 22 ARC 20-Inch AR-15 Barrel

Build a flat-shooting 22 ARC upper around a barrel from CMMG, a name AR builders know. Browse more AR-15 barrels and order from our Lubbock, Texas gun shop for direct shipping.