.45 Colt - Cartridge Loads

Cartridge Loads

The .45 Colt originally was a blackpowder cartridge, but modern loadings use smokeless powder. The original blackpowder loads called for 28 to 40 grains (1.8 to 2.6 g) of blackpowder behind a 230-to-255-grain (15 to 16.5 g) lead bullet. These loads developed muzzle velocities of up to 1,000 ft/s (300 m/s). Because of this power and its excellent accuracy, the .45 Colt was the most-used cartridge at the time of its introduction, succeeding the .44 WCF (or the .44-40 Winchester). The .45 Colt never enjoyed the .44-40's advantage of a Winchester rifle chambered for it, allowing use of the same cartridge in both pistol and rifle. The reason was that early .45 Colt cartridges had a very minimal rim, and would not eject reliably. Currently manufactured brass has a rim of adequate diameter for such uses. Modern Winchesters, Marlins and replicas have remedied this omission almost 100 years after the fact, and the .45 Colt is now available in modern lever-action rifles. While this has been one of numerous arguments to explain the lack of a rifle chambered in .45 Colt, in fact, Colt would not authorize the use of their .45 Colt in other manufacturers’ arms. It required the expiration of those original patents for the .45 Colt to become available in a lever action or indeed in any other action rifle.

Today's standard factory loads develop around 400 ft·lbf (540 J) of muzzle energy at about 860 ft/s (260 m/s), making it roughly equivalent to modern .45 ACP loads. There are Cowboy Action Shooting loads which develop muzzle velocities of around 750 ft/s (230 m/s).

Some handloads and factory manufactured cartridges put this round in the same class as the .44 Magnum. These loads cannot be used in any original Colt Single-Action Army or replica thereof, such as those produced by Uberti, Beretta, the Taurus Gaucho, or the Ruger New Vaquero, as these guns are built on the smaller frame with thinner cylinder walls. These loads should be used only in modern large-frame revolvers such as the Ruger Blackhawk, Redhawk, Ruger Vaquero (erroneously referred to as the "Old Model" to differentiate it from the "New Model"), Thompson Center Contender or any gun firing the .454 Casull cartridge. Modern rifles with strong actions (such as the Winchester Model 1894, Marlin Model 1894, and new clones of the Winchester Model 1892) chambered for the cartridge can safely handle the heavier loadings.