Barnes Supressor Series Subsonic is a purpose-built ammunition line engineered for the coming surge in suppressor ownership featuring premium Sierra projectiles loaded to Barnes'exacting standards. Initial subsonic offerings use clean-burning propellants to minimize gas blowback. This load is not designed to cycle semi-automatic or fully automatic rifle platforms. While it may be fired in these firearms, the action will not cycle and the bolt must be manually charged after each shot.Supersonic variants are planned for future release to broaden performance options, making Suppressor Optimized a product family that grows with customer needs. This ammunition is new production, non-corrosive, in boxer primed, reloadable brass cases.