csimile. This is the first edition of one of the classic descriptions of wildcat cartridges, first published in 1949. Though revised and updated in 1962, this is Ackley's first effort at tackling the loading data, theory, and practice of wildcat cartridges. A wildcat cartridge, often shortened to wildcat, is a custom cartridge for which ammunition and/or firearms are not mass-produced. These cartridges are often created in order to optimize a certain performance characteristic (such as the power, size, or efficiency) of an existing commercial cartridge. Developing and using wildcat cartridges does not generally serve a purpose in military or law enforcement; it is more a hobby for serious shooting, hunting, gunsmithing and handloading enthusiasts, particularly in the United States.