Faxon Firearms Duty Series Gunner AR-15 5.56 NATO 13.9" Barrel - Black Nitride

The Faxon Firearms Duty Series Gunner is a standalone AR-15 barrel chambered in 5.56 NATO. Its 13.9" barrel length and universal AR-15 fit make it a purpose-built component for a mid-length direct-gas-system build, not a complete firearm or upper assembly.

Built from 4150 chrome-moly-vanadium steel, this barrel uses conventional button rifling with a 1:8 twist. The Gunner contour keeps a Government-style taper from the barrel extension to the gas block, then transitions to a lighter Pencil-style contour forward of the gas block to balance mass and heat resistance at the rear with reduced weight toward the muzzle. A black nitride treatment is applied to the bore and exterior.

The barrel features 1/2x28 muzzle threads, an 11-degree target crown, and an M4-pattern barrel extension. Its gas-block interface has a 0.625" diameter, 1.9" journal length, and 0.081" gas port. Made in USA, each barrel is stress relieved, air-gauge tested, magnetic-particle inspected, and individually checked for headspace. This is a New barrel component.