This 18" 6MM ARC barrel is machined from 416 Stainless Steel with a bead blasted finish. Our Premium Series Barrels feature a Nickel Boron Coated Extended M4 Feed Ramp Extension.Featuring functionally aggressive flutes and crisp, clean lines, BA Fluted barrels deliver the perfect balance of weight and rigidity. Utilizing six and eight flute designs we've achieved weight reduction up to and exceeding 16 ounces. Confidently lighten your kit without sacrificing an ounce of accuracy.SKUBABL6MM002PLLength18"MaterialHardened 416R Stainless SteelProfileSPRFinishFluted Bead BlastedTwist Rate1/7"Gas System LengthRifleGas Block Journal.750"Muzzle5/8x24 ThreadedWeight (oz)41.3oz