300 BLK barrel with pistol gas system for optimum reliability with super or subsonic ammo.Faxon Firearms barrels are an incredible value. All Faxon barrels are fully stress relieved, air-gauge tested, and 11 degree target crowned for excellent accuracy.All Faxon Barrels start with quality 4150 or 416-R Stainless steel, and go through a series of of tests at each operation until finished in Nitride and final inspected. All barrels are individually checked for headspace.Faxon manufactures all their barrels in Cincinnati, Ohio under their ISO:9001 and AS:9100 quality certifications.Features: Barrel Material: 416-R Stainless Steel Barrel Type: 5R Button Rifled Barrel Caliber: 300BLK AAC Barrel Twist: 1:8 Barrel Length: 9 Barrel Profile: Gunner Barrel Gas System: Pistol Inside Finish: QPQ Nitride Outside Finish: QPQ Nitride Muzzle Thread: 5/8-24 Gas Block Diameter: .750 Gas Block Journal Length: 1.9 Barrel Extension: M4- Nickel Teflon Coated Weight: .97 lbs Magnetic Particle Inspected! 11-degree Target Crown