The barrel is one of the most critical components of your build. We only offer high quality barrels so you can be confident that your rifle will be off to a good start with which ever barrel you decide on.Features: 8.1" Cold Hammer Forged Barrel DIN 21CrM0V511 1/7 Twist Rate 1/2 X 28 Thread Pitch for Muzzle 5.56 NATO Chamber .750 Gas Block Seat Requires Pistol Length Gas Tube M4 Feed Ramped Barrel Extension Black Nitride Inside and Out Weight: 1lb 2oz