Dick Casull

Richard J. Casull (/kəˈsuːl/) (February 15, 1931 – May 6, 2018)^[1] was an American gunsmith and wildcat cartridge developer whose experiments with .45 Colt ammunition in the 1950s led to the creation of the .454 Casull cartridge. Casull, whose passion was six-shooters, was determined to create high-velocity rounds for the .45 Colt. His goal was to achieve a muzzle velocity of 2,000 feet per second with Colt .45 rounds fired from a single-action Army-style revolver with a 7+1⁄2-inch barrel. This proved impossible due to the tensile strength of the Colt .45 cylinder, so he set out to develop his own casing and bullet.

Casull began his career as a wildcat cartridge developer after having contact with Elmer Keith in the 1940s, an Idaho rancher, firearms enthusiast, and author. Keith was instrumental in the development of the first magnum revolver cartridge, the .357 Magnum, as well as the later .44 Magnum and .41 Magnum cartridges. Casull was instrumental in the development of various wildcat cartridges, a few of which were later adopted as factory rounds.

Casull also worked with Oregon-based gunsmith P.O. Ackley, who developed a family of improved wildcat cartridges by rechambering extant firearms and fireforming^{[clarification needed]} the ammunition to decrease body taper and increase shoulder angle, resulting in a higher case capacity. Ackley not only improved standard cartridges but also created the first .17 caliber (4.5 mm) centerfire cartridge. He developed the .450 Ackley Magnum (based on a .375 H&H Magnum case necked up to .458) and the .475 Ackley Magnum (based on a .375 H&H Magnum necked up to .475 (12 mm)).