Fired cartridges will always have a carbon residue left on the primer pockets, which must be removed for uniform primer ignition. The Hart primer pocket cleaner will assist you in removing this carbon. This product is made of stainless steel, with a high speed steel cutter. This can be attached to either a hand held or powered screwdriver. By rotating the head, this can be used for either large or small primer pockets. 1/16″ Allen wrench included.