The Faxon 10.5" Socom profile barrel is manufactured from 4150 chrome moly steel and nitride coated inside and out for amazing corrosion resistance and durability. Carbine gas for longevity and reliability. Faxon Firearms barrels are the pinnacle of value and performance. Manufactured in-house from bar stock, these barrels are button-rifled and air-gauge tested to ensure superior accuracy. Barrel Material: 4150 CMV Steel Barrel Type: Button Rifled Barrel Caliber: 5.56 NATO Barrel Twist: 1:8 Barrel Length: 10.5" Barrel Profile: Socom Barrel Gas System: Carbine Inside Finish: Nitride Outside Finish: Gun Metal Grey Cerakote Muzzle Thread: 1/2-28 Gas Block Diameter: .750" Gas Block Journal Length: 1.9" Barrel Extension: M4 Weight: 1.10 lbs Magnetic Particle Inspected! 11-degree Target Crown