Faxon Duty Series 5.56 NATO 20″ 1:8 Nitride Barrel

The Faxon Firearms Duty Series barrel is a 20″ barrel chambered for 5.56x45mm NATO (.223 Rem) designed for AR-15/M16 platforms. It is manufactured from 4150 steel and finished inside and out with a QPQ-style black nitride process. The barrel features a 1:8″ twist rate and an 11° target crown intended to support precision and consistent performance. This barrel uses a rifle-length gas system and ships threaded for muzzle devices.

Key Specifications

• Chambered for 5.56x45mm NATO (.223 Rem).
• Barrel length is 20 inches.
• Twist rate is 1:8″ to stabilize a broad range of projectiles.
• Barrel material is 4150 steel.
• Finish is QPQ black nitride on the inside and outside.
• Muzzle threads are 1/2-28.
• Gas system length is rifle-length.
• Gas block journal measures 1.9 inches.
• Features an 11° target crown to support consistent muzzle alignment and accuracy.

Engineered and finished with the manufacturing controls described in the product literature, this Duty Series barrel is suited for accuracy-focused builds and extended training sessions where consistent performance and durability matter. Its 20″ length and rifle-length gas system make it appropriate for shooters prioritizing a balance of velocity and controllability in a full-length AR configuration.