Cimarron 1865 Spencer Repeating Carbine 45 LC, 20-Inch Round Barrel Case Hardened Frame, Walnut Stock Rifle

The 45 Colt (45 Long Colt) was introduced in 1873 in Colt's Single Action Army. Adopted by the U.S. military in 1875, it served until 1892 when it was replaced by the less powerful (and unsatisfactory) 38 Long Colt. Originally loaded with 40 grains of blackpowder and a 255-grain bullet the 45 Colt produced about 900 feet per second for more than 400 foot-pounds of energy, a powerful handgun cartridge for its day--and any day. Using a .454-inch bullet, today's standard load retains the 255-grain bullet at 860 fps. Lighter bullets at somewhat higher velocities are available. 45 Colt was the most common chambering in Colt's single action. Today it is chambered in virtually all centerfire single-action revolvers and has been chambered in numerous large-frame double-action revolvers. 45 Colt is the most popular revolver cartridge in cowboy action shooting, and remains a powerful and effective personal defense cartridge, its only drawback being the necessity for a large revolver to house it. — Craig Boddington