The standard barrel at Faxon value and quality. 4150 balances accuracy, longevity, and swing. 4150 QPQ coated inside and out for amazing corrosion resistance and durability.Faxon Firearms barrels are the pinnacle of value. Manufactured 100% in-house from cradle-to-grave, these barrels are fully stress releived, 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 Barrel Type: Button Rifled Barrel Caliber: 5.56 NATO Barrel Twist: 1:8 Barrel Length: 14.5 Barrel Profile: Gov't/SOCOM Barrel Gas System: Mid Length Inside Finish: QPQ Nitride Outside Finish: QPQ Nitride Muzzle Thread: 1/2-28 TPI (Threads Per Inch) Gas Block Diameter: .750 Gas Block Journal Length: 1.9 Barrel Extension: M4 Weight: ~1.50 lbs Magnetic Particle Inspected 11-degree Target Crown