.45 Colt (Rifle) (using Sierra bullets)
Date: Feb 04 2021
The .45 Colt was developed in 1872 for the Model 1873 Colt Single Action Army revolver (aka Peacemaker) and adopted by the U.S. Army in 1873. It was originally a black-powder cartridge, and due to its large caliber and heavy bullet, earned a reputation as a fight-stopper. It also proved valuable for big-game hunting as a standard sidearm on the frontier. Factory loads from the 1880s that contained 40-grains of black powder with 250/255-grain bullets reached roughly 1,000 fps and were the “magnum” cartridge and load of that era.
By around 1900, factory loads began to appear that contained smokeless powders, with the velocities being reduced to around 870 fps. Today pressures have been standardized at 14,000 psi, and velocities from Winchester and Remington are 860 fps.
When stronger guns began to appear, such as the Ruger Blackhawk and many others, handloaders began to load the cartridge to much greater pressures to increase performance. Several small ammunition factories are offering such loads, but they are not endorsed by SAAMI and are proprietary loads designed to be fired in specific firearms. Many of these loads generate up to 32,000 CUP. Following the use of more modern piezoelectric pressure testing equipment, some of these loads have been recorded at near 35,000 psi. Either of the above listed pressures will destroy black-powder-era guns, or guns that are of a weaker design.