Noveske's AR-15 Match Barrels feature their exclusive 5.56 Match Mod 0 Chamber, designed to offer outstanding accuracy with both 5.56x45mm NATO and 223 Remington ammunition. Composed of Cold Hammer Forged Steel, the bore is given improved polygonal rifling that slightly boosts projectile velocity and reduces the speed of the bore's erosion, meaning superior accuracy retention that outlasts that of barrels with conventional rifling. All Noveske match barrels have a bead-blasted satin finish, M4 extended feed ramps, and are threaded at the muzzle for the addition of flash hiders, muzzle brakes and/or sound suppressors. FeaturesMagnetic Particle InspectedGas tube includedNoveske marked gas block: Low profile, .750" journal, pinned to barrelM4 barrel extension