Jeffrey Locke again. My rationale for using the X-frames as my platforms and a shorter cartridge of similar power in each is twofold. First, the idea of bullet-creep tying up and disabling the gun is mitigated by using the shorter cartridge in the longer cylinder of the X-frame. Secondly, the shorter barrels do not burn gun powder as well as longer barrels. Using a 5 inch barrel in the 460 and a 6 1/2 inch barrel in the 500 means the shorter cases of the 454 Casull and 500 JRH will burn their powder more effectively than the 460 Smith and Wesson Magnum and 500 Smith and Wesson Magnum.