One Horse AR-15 Barrel Features The One Horse AR-15 barrel is machined from 4150 chrome-moly-vanadium steel a material chosen for its strength and heat resistance under sustained firing. Its 1:7 twist rate stabilizes a wide range of 5.56mm bullet weights from lightweight 55-grain loads up to heavier 77-grain match projectiles. The M4 profile and government contour balance weight savings with the durability needed for hard use whether on a duty carbine or a range gun. A QPQ finish coats the barrel for added corrosion resistance in humid or wet environments. An extended M4 feed ramp also QPQ coated improves feeding reliability across a range of magazine types and ammunition. The carbine-length gas system is tuned for standard 16-inch AR-15 builds giving reliable cycling with common carbine-length gas blocks and handguards. A 1/2x28 threaded muzzle accepts standard AR-15 muzzle devices compensators or suppressors. This barrel is a straightforward drop-in option for builders looking to upgrade or replace a worn factory barrel. One Horse AR-15 Barrel Specifications Brand: One Horse Model: AR-15 Barrel Caliber: 5.56 NATO Barrel Length: 16 Barrel Profile: M4 Muzzle Thread: 1/2x28 Twist Rate: 1:7 Gas System: Carbine Length Material: 4150 Steel Finish: QPQ Available At: GrabAGun