included Ruger Old Model and New Model Blackhawks, and Smith & Wesson K-frames (Models 10, 14, 15, and 19). Colt produced one Python in this caliber as a prototype and retains it in their museum. Gallery See also Table of handgun and rifle cartridges References .256 Winchester Magnum. (KNOW YOUR CARTRIDGE). Gun Digest, 2013 Jan 14, p. 17(1) (). 256 Winchester Magnum 256 Winchester Magnum