Diamondback DB 5.56mm NATO Vanadium Steel Rifle Barrel - 16in - Black Nitride - Precision machined from heavy duty 4150 Chrome Moly Vanadium Steel, this barrel features a 6 groove button rifled bore to ensure consistent accuracy, with a 1: 8 twist rate optimal for a variety of bullet weights. The mid-length gas system is designed for reliable and smooth cycling. This barrel is threaded 1/2 x 28 and features an 11 degree target crown. To provide an added layer of protection, the barrel is finished with a durable salt bath Nitride coating. Designed by Diamondback Barrels Co., this barrel also features M4 feed ramps and is compatible with a wide range of AR-15 parts. The medium contour/profile of the barrel provides a good balance of weight and heat dissipation. Threaded Barrel: 1/2 x 28 Caliber: 5.56mm NATO Color: Black Material: Chrome Moly Vanadium Steel Finish: Black Nitride Barrel Type: Midlength Medium Profile Twist: 1: 8 Length: 16in