Faxon Firearms Duty Series Barrel Features The Faxon Firearms Duty Series Barrel is built around the Gunner profile which combines the durability of the Government profile near the chamber with the weight savings of a Pencil profile forward of the gas block. This design removes unnecessary weight from the front of the barrel while keeping material toward the rear maximizing heat resistance and minimizing barrel whip during rapid strings of fire. Chambered in 5.56 NATO with a 1 in 8 twist rate the barrel is button rifled from 4150 chrome moly vanadium steel for consistent accuracy shot after shot. The mid length gas system and 0.625 inch gas block diameter provide smooth reliable cycling across a range of ammunition. Each Faxon barrel is manufactured one hundred percent in house fully stress relieved air gauge tested and finished with an 11 degree target crown to maximize accuracy at the muzzle. The salt bath nitride finish applied both inside and out resists corrosion and wears evenly over thousands of rounds. Threaded 1/2x28 at the muzzle this barrel accepts standard AR-15 muzzle devices without modification. At 1.26 pounds the Duty Series Barrel is a proven American made upgrade ready for sale at GrabAGun. Faxon Firearms Duty Series Barrel Specifications Manufacturer: Faxon Firearms Model: Duty Series Barrel Caliber: 5.56 NATO Color: Black Material: 4150 CMV Steel Finish: Nitride Barrel Type: Button Rifled Twist: 1:8 Barrel Length: 13.9 Barrel Profile: Gunner Gas System: Mid Length Gas Block Diameter: 0.625 Muzzle Thread: 1/2x28 Compatible Hosts: AR-15 Weight: 1.26 lbs Available At: GrabAGun