Military-style semi-auto rifles seldom have firing pin retraction springs. If care is not used in assembling ammunition, a "slam-fire" can occur before the bolt locks. The military arsenals accomplish this using different techniques and components, including different primer sensitivity specifications from their commercial counterparts. CCI makes #34 primers for 7.62mm rifles for commercial sale that match military sensitivity specs that reduce the chance of a slam-fire when other factors go out of control*. If you're reloading for a military semi-auto and are looking for CCI #34 primers for 7.62mm, look to CCI Military primers. *Effective slam-fire prevention requires more than special primers. Headspace, chamber condition, firing pin shape and protrusion, bolt velocity, cartridge case condition, and other factors can affect slam-fire potential. Key CCI #34 Standard Primers specifications: Mil-spec sensitivity Initiator mix optimized for ball/spherical propellants Use the same data as CCI Magnum primers Military-style semi-automatic rifles CCI #34 primers for 7.62mm rifles are crafted to minimize slam-fire risks, matching military standards. Buy CCI Military primers now!