This 350 Legend chambered 18 inch Performance Series Barrel is machined from CrMoV steel with a QPQ Corrosion Resistant Finish. Our Performance Series barrels feature a Nickel Boron Coated Extra Wide Feed Ramp Extension. Product Specifications Length: 18" Material: Chrome Moly Vanadium Profile: SPR Finish: QPQ Corrosion Resistant Twist Rate: 1/16" Gas System Length: Carbine Gas Block Journal: .750" Muzzle: 1/2x28 Threaded Weight (oz): 41oz Other Info: HP and MPI Tested