Reduced-weight bolt/carrier assembly helps tame felt recoil on a JP or DPMS or Remington AR-style .308 rifle (LR-308 pattern only). Carrier features the same type of weight-reducing cuts found on the original JPBC-3 AR-15 bolt carrier to give the same benefits your .308. Wide carrier rails have extra bearing surface to improve bolt alignment and reduce wear. Carrier key is already installed and staked. Available with QPQ or polished stainless finish. See SPECS for the Compatibility Notice. Mfg: J P Enterprises SPECS: JP Low Mass Operating System Bolt Carrier- Large-Frame (.308). Stainless Steel. Polished Finish. Requires DPMS-pattern bolt, firing pin and cam pin. Weight: 10.82 oz. with key installed. JP Low Mass Operating System Bolt Carrier- Large-Frame (.308). Stainless Steel. QPQ Black Finish.