This fine Windham Weaponry Barrel – chambered for 7.62 X 39mm Caliber – is 16″ in length, turned in an M4 profile, and includes the Barrel Extension, Barrel Nut, Front Handguard Cap, Mil Std 1913 Railed Sight Base with Sling Swivel and Bayonet Lug. Machined from 4150 Chrome Moly Vanadium 11595E Steel, this highly accurate barrel is Chrome Lined in both Bore and Chamber for long wear and ease of cleaning. A Black Manganese Phosphate finish offers protection against rust and corrosion. Rifling is 1 turn in 9.5 inches – right hand twist – with 4 lands & grooves for optimum accuracy with a wide range of 7.62 X 39mm ammunition. The muzzle is threaded 5/8″ x 24 T.P.I. to accept a variety of flash hiders or muzzle brakes. Includes Bolt.