The barrel is one of the most critical components of your build. We only offer high quailty barrels so you can be confident that your rifle will be off to a good start with which ever barrel you decide on.Features: 8.3" Premium Barrel Machined From Douglas Blank 1/8 Twist Rate 5/8 X 24 Thread Pitch for Muzzle .300 Black Out Chamber .750 Gas Block Seat M4 NIB Coated Barrel Extension Black Nitride In and Out Pistol Gas Weight: 1lb 2oz