A case usually made of brass or copper, containing the powder charge, the primer and the bullet. (Before development of the metallic cartridge, the term was used to mean a roll or case of paper containing powder and shot. Modern cartridges are generally classified in three categories: Center fire metallics, Rim fires and Shot shells. Centre fire metallics, include all metal cartridges that have primers in the center of the base. Rim fires include all cartridges in which the priming powder is sealed in the soft rim around the base. Shots hells include all cartridges that contain shot, or small pellets, instead of a single bullet.)