Various mechanical features of the Colt M1911 A1 auto pistol have prevented any significant ballistic advantage in the cartridges it chambers. One of these weaknesses is that a portion of the cartridge head is unsupported so operating pressures are dictated by the strength of that portion of the case. The 45 Winchester Magnum has a substantially stronger case head and dimensions identical to the 45 ACP except for greater length. In their search for a more potent 45 caliber round for their 45 caliber pistols, the Detonics Mfg. Co. decided to take advantage of this by trimming the 45 Winchester Magnum from its normal length of 1.198 inches to that of .942 inch. This is still sufficiently longer than the 45 ACP so that the 451 Detonics cartridge will not chamber in handguns intended for the 45 ACP. The newly created case will handle much higher pressures than the original 45 ACP and still function through actions of the same length. The idea of a more powerful 45 ACP cartridge has long intrigued 45 auto buffs. The 451 Detonics was a viable solution to what has heretofore been an insoluble problem. A 185 grain bullet at 1353 fps and a 200 grain at 1281 fps is a significant boost to the usual 45 ACP performance of a 230 grain at 850 fps. Recoil at this top loading gets rather heavy, so most users of the 451 will want to stay below the top loads. The 451 Detonics is a good self defense or field cartridge for small game or varmint shooting.
This text is based on information from “Cartridges of the
World”, Hodgdon reloading manual, the cartridge designer and/or