Think back to the days when America had two major handgun manufacturers: Colt and Smith & Wesson. Now consider this when speaking of their big-bore handguns: Smith & Wesson was identified more often with a .44 caliber, as in .44 Russian and .44 S&W Special, but for Colt it was .45’s. First came the .45 Colt in 1873 with a revised version in 1909. Then, beginning in the early 1900s, the company began toying with a rimless .45 for use in autoloading pistols. Of course that became the .45 ACP.
The operating characteristics of modern rifles and handguns where terminal impact are concerned are so different as to be differences not in degree but in kind. Modern, high-velocity rifle cartridges – and by “modern” I mean any of the bottle-necked, smokeless powder cartridges beginning with the .30-40 US Army and the even more famous and durable Caliber .30, US, Model of 1906 – depend on high impact velocity, bullet deformation and hydrostatic shock to kill. The high velocities obtainable with a rifle case means that the rifle bullet makes excellent use of the “V” in the basic physics equation E=MV2. Pistol cartridges, even the modern versions cannot generate the velocities that rifle cartridges can, and so the M side of the equation becomes important.
That’s where the .45 gets its advantage. After well over a hundred years, the stopping power of a big, heavy bullet hasn’t changed. Many, many shooters still favor the .45, including yr. obdt, being the owner of five .45 caliber pistols (RAA 1911, Glock 36, Glock 21, Ruger Vaquero, Smith & Wesson 25-5.)
Even so, a handgun cartridge still pales in comparison to even a medium-power rifle cartridge, a distinction that many not familiar with firearms fail to understand. By way of illustration, there’s an old story about an aged policeman who showed up for his retirement ceremony wearing his sidearm. A lady in the group assembled for the celebration noted the holstered pistol and asked him if he was expecting trouble. “No ma’am,” he replied. “If I was expecting trouble I’d have brought my rifle.”