The .44 Magnum is a large-bore, dual-use cartridge designed for revolvers; however it is also used in many rifles as well. It was developed in the mid-1950s by lengthening the .44 Special cartridge. Despite the ".44" designation, all guns chambered for .44 Magnum and its parent use bullets .432 inches (10.97 mm) in diameter2002, Lyman Reloading Handbook, 48th edition.