Faxon Firearms Big Gunner Duty Features The Faxon Firearms Big Gunner Duty barrel is machined from raw 4150 CMV bar stock at Faxon s Cincinnati facility and is fully stress-relieved air-gauge tested and Magnetic Particle Inspected before it ships giving the shooter confidence in a barrel that has been checked at every stage of production. The Big Gunner contour balances rigidity with weight savings on a pistol-length gas system and the M18x1.5 threaded muzzle with tapered shoulder comes with an adapter included for mounting compatible muzzle devices. Every barrel is individually checked for headspace with precision custom hardened gauges ensuring a reliable fit on AR-10 pattern builds. This level of quality control is what separates a duty-grade barrel from an off-the-shelf option. Riding on a standard DPMS Gen 1 .308 extension finished in black oxide the Big Gunner Duty barrel drops onto AR-10 platform rifles and pistols with minimal fitting required. The .875 gas block diameter and 1.9 gas block journal length are sized for common aftermarket gas blocks simplifying a build or barrel swap. Salt Bath Nitride treatment on the bore and exterior resists corrosion and wear while easing cleaning after extended range sessions. For AR-10 builders chasing the 8.6 Blackout cartridge s terminal performance in a pistol-length package this Faxon barrel delivers a proven warrantied foundation. Faxon Firearms Big Gunner Duty Specifications Brand: Faxon Firearms Model: Big Gunner Duty Type: Barrel Caliber: 8.6 Blackout Compatible Hosts: AR-10 Barrel Length: 12 Twist Rate: 1:3 Barrel Profile: Big Gunner Gas System: Pistol Length Barrel Material: 4150 CMV Steel Rifling: Button Finish: Salt Bath Nitride Color: Black Oxide Muzzle Thread: M18x1.5 Gas Block Diameter: .875 Barrel Extension: Standard DPMS Gen 1 .308 Extension Black Oxide Crown: 11-Degree Target Crown Weight: 2 lbs Available At: GrabAGun