This .308 chambered (DPMS style) 18 inch barrel is machined from 416R Stainless Steel with a QPQ corrosive resistant finish. Our Premium Series Barrels are HP and MPI tested, ensuring the best quality and accuracy. Hanson Series Barrels feature our proprietary BA Hanson profile, including a pinned lo-pro gas block. Hanson barrels are not designed to work with aftermarket piston kits.