Definitions for ".45 Colt"
The .45 Colt cartridge (known commonly as the ".45 Long Colt ") was developed by the US Army at Frankfort Arsenal in 1872 as a improvement of the british .476 Eley to replace the standard issue Smith and Wesson .44 round in the famous Colt Single Action Army, often known as the Peacemaker single action revolver. The US Army adopted the cartridge in 1873 and it remained in use until 1877 when the army went to the M1877 ball revolver load. The new round was shorter than the original in case lenght and used a reduced powder charge of aproximately 30 grains of black powder vs the 40 grains in the original.