Faxon Firearms barrels are the pinnacle of value. Manufactured 100% in-house from cradle-to-grave, these barrels are fully stress relieved, air-gauge tested, and 11 degree target crowned to ensure superior accuracy.Quality is imbued into our barrels from the start. We start with the best materials, either certified 4150 Mil-Spec steel or 416-R Stainless. From there, each barrel goes through a battery of tests at each operation until finished in Nitride and final inspected. All barrels are individually checked for headspace by precision custom hardened gauges. Barrel Material: 4150 GBQ Steel Barrel Type: Button Rifled Barrel Caliber: 5.56 NATO Barrel Twist: 1:8 Barrel Length: 7.5 Barrel Profile: Gov't/Socom Barrel Gas System: Pistol Inside Finish: QPQ Black Nitride Outside Finish: QPQ Black Nitride Muzzle Thread: 1/2-28 TPI (Threads Per Inch) Gas Block Diameter: .750 Gas Block Journal Length: 1.9 Barrel Extension: M4 Weight: .89 Lbs Magnetic Particle Inspected 11-degree Target Crown