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 rifle primers for commercial sale that matches 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, 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. Features: Mil-Spec sensitivity Initiator mix optimized for ball/spherical propellants Use the same data as CCI magnum primers Military style semi-automatic rifles #html-body [data-pb-style="62DF828888FB2"]{justify-content: flex-start; display: flex; flex-direction: column; background-position: left top; background-size: cover; background-repeat: no-repeat; background-attachment: scroll; border-style: none; border-width: 1px; border-radius: 0px; margin: 0px 0px 10px; padding: 10px;}#html-body [data-pb-style="62DF828888FBF"]{border-style: none; border-width: 1px; border-radius: 0px; margin: 0px; padding: 0px;}