Diamondback DB M4 Profile 5.56mm NATO Vanadium Steel Rifle Barrel - 16in - Black Nitride - The DB Barrel is optimized with a 1:8in twist rate, ensuring excellent stability for a wide range of bullet weights. The carbine-length gas system provides smooth and dependable cycling, while the medium/M4 profile offers a lightweight yet rigid construction for improved handling and accuracy. The Nitride finish gives the barrel a sleek, black coating that enhances its durability and appearance. Whether you're upgrading an existing rifle or building a new platform, the Diamondback DB Barrel offers consistent performance and exceptional value. 1:18 Threaded Barrel: 1/2 x 28 M4 Feed Ramps Carbine Length Gas System Medium/M4 Profile, Carbine-Length Gas System