The Ballastics Advantage 18 .223 Wylde SPR Fluted Rifle Length AR 15 Premium Series Barrel is machined from 416R 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. Gas block journal is .750.