Faxon Firearms barrels deliver exceptional value and precision. Manufactured in-house in Cincinnati, Ohio, each barrel is fully stress relieved, air-gauge tested, and finished with an 11 target crown for improved accuracy. Built from certified 4150 CMV or 416R stainless steel, barrels are inspected and tested throughout production, finished in nitride, and individually checked for correct headspace with precision PTG gauges. Magnetic particle inspected. Product Details Barrel Material: 4150 CMV Barrel Type: Button Rifled Caliber: .400 Legend (SAAMI) Barrel Twist: 1:16 Barrel Length: 16" Barrel Profile: Gunner Gas System: Carbine Inside Finish: Nitride Outside Finish: Nitride Muzzle Thread: 11/16" x 24 TPI Gas Block Diameter: 0.875" Gas Block Journal Length: 1.9" Barrel Extension: Big Bore Weight: 2.00 lbs Inspections & Testing: Fully stress relieved Air-gauge tested Magnetic particle inspected Individual headspace check with PTG gauges Muzzle: 11 target crown Manufactured in Cincinnati, Ohio