 It was originally called the .224 Weatherby Varmintmaster when it was introduced alongside the Weatherby Varmintmaster rifle, but the rifle was discontinued in 1994 and the cartridge was renamed.The cartridge design began years earlier but its introduction was delayed, at least in part, because of the unavailability of a suitable action.An earlier high-velocity .22 caliber round from Weatherby called the .220 Weatherby Rocket was based on the .220 Swift though it was unsuccessful and never manufactured.