The question often comes up about preferences of .45 Colt, .45 ACP, or convertable in revolvers. A number of years ago I tried out several guns, Colt M1917, Smith M1917, Smith 625, and Ruger Blackhawks.

First, the .45 ACP revolvers: The early Colts require half-moon or full moon clips, as the cylinder was straight bored and the cartridges had no "step" on which to headspace. Later guns did incorporate this feature, as did all Smith & Wessons. All required clips for positive extraction, there being no rim on the ACP case for that purpose. In the 1920s a thick rimmed .45 cartridge, the .45 Auto Rim, was introduced to eliminate the need for clips. Generally, these guns had long cylinders, which meant a long bullet travel in the cylinder throat. Used with jacketed, ball type ammunition, accuracy was not the best as the hardball bullet had a rather short bearing surface. Later target type wadcutter bullets had more bearing surface and provided improved accuracy.

The .45 Colt revolvers had equal accuracy problems, with varying bore/chamber throat dimensions. With bore and chamber dimensions standardized, the .45 Colt began to shine. Especially with the coming of the heavy framed Ruger Blackhawk. Handloaders found that heavy bullets, intended for .45-70 rifle loads, could be sized down and loaded to some high velocities in the .45 Colt when used in Rugers. I've loaded 350 gr. lead bullets to velocities reported around 1300 fps. I never took anything with this, but have read reports of its use or buffalo and bears.

The convertible revolver, the single action, merely requires swapping cylinders to change from one round to the other. And no clips are required with the rod-ejecting SA. Without modification, .45 Auto Rim cannot be used in the Ruger convertible, as there is not enough headspace for the thick rim. The .45 Cowboy round, or the .454 Short, can be used in an un-altered .45 ACP single action cylinder.

For Cowboy Action Shooting, the .45 Colt is the natural choice. For maximun power, the Ruger in .45 Colt. For a DA revolver, the Smith .45 ACP.

Bob Wright
Pontificatin' again