Buy Remington Large Rifle Magnum Primers Online. Purchase a box of 1000 Remington Large Rifle Magnum Primers #9-1/2M. (10 Trays of 100). Every Remington primer has a collection of parts that were meticulously built with precise tolerances. The priming mix is precisely developed for consistent ignition with a wide range of powder types, and the primer cup dimensions are regulated to.0001′′. Primers are put through reliability tests between -20 and +150 degrees F. Even with off-center firing pin hits, the distinctive tripod anvil design offers a bigger strike area with optimum sensitivity. Purchase a box of 1000 Remington Large Rifle Magnum Primers #9-1/2M. (10 Trays of 100).