Robb, strippers are sheet steel or soft brass devises to hold individual cartridges in a collective row. They are then inserted into a milled slot in older rifles and some pistols. You then load the fixed magazine by pushing ( stripping) the cartridges down with your thumb. Many modern detachable magazines can be rapidly charged with a detachable stripper guide. These are the correct "clips" often erroneously confused with true cartridge magazines. They make for faster reloading and keeping ammunition organized.