Faxon .308 WIN 18" Big Gunner Barrel

Faxon .308 WIN 18″ Big Gunner Barrel

11-degree target crown, MPI Inspected

The Faxon .308 WIN 18″ Big Gunner Barrel is a precision-engineered solution for shooters who want the perfect balance of weight, accuracy, and performance in their large-frame AR build. Machined from 4150 Chrome Moly Vanadium (CMV) steel and finished with a QPQ salt bath nitride treatment, this barrel delivers long-lasting corrosion resistance, superior surface hardness, and smooth performance under pressure.

Like all Faxon barrels, this 18″ Big Gunner model is 100% manufactured in-house from gun-barrel-quality bar-stock and subjected to a rigorous testing process. Each barrel is MPI (Magnetic Particle Inspected) to confirm the steel’s integrity and is individually checked for headspace using precision custom hardened gauges to ensure safe and consistent chambering and function.

Configured with a rifle-length gas system and a 0.75″ gas block journal, this barrel offers smooth recoil management and reliable cycling—ideal for both precision shooting and field use. The M4 feed ramp extension is Nickel Teflon coated, promoting reliable feeding even in high-stress or high-volume shooting environments.

What is the Big Gunner Profile?
The Big Gunner profile is Faxon’s evolution of their popular Gunner profile, blending the best characteristics of the Government and Pencil profiles. From the barrel extension to the gas block, the profile follows a Government-style taper for improved heat resistance and structural integrity. Forward of the gas block, the profile transitions to a lightweight pencil contour to reduce front-end weight. This redistribution of material enhances maneuverability and point-of-aim stability while mitigating whip and heat distortion during extended firing.

Key Features:

• Caliber: .308 Winchester
• Barrel Length: 18″
• Material: 4150 Chrome Moly Vanadium (CMV) Steel
• Finish: QPQ Salt Bath Nitride (inside and out)
• Crown: 11-degree target crown for precise muzzle exit
• Feed Ramp Extension: Nickel Teflon-coated M4 extension
• Gas System: Rifle-length
• Gas Block Diameter: 0.75″
• Profile: Big Gunner – Government taper to Pencil front
• Headspace: Individually checked with precision hardened gauges
• MPI Inspected: Confirms steel integrity for safety and longevity