Premium Grade Stainless AR-15 Rifle Barrel, 16" M4 Contour Barrel, 1 in 8 twist. Gas port drilled for carbine length gas setup, and threaded for a compensator. Barrel extension in rear with M4 feed ramps. Chambered for .223 Wylde to accommodate commercial .223 Remington or 5.56 NATO. Made from 416R Stainless with a Stainless finish. Thread Pitch: 1/2 x 28; Gas Block Diameter: 0.750. Gas System: Carbine. Not chrome lined.