.45 Colt (.45 Long Colt, .45 LC)

The .45 Colt  is one of the oldest revolver cartridges still in production today. It was introduced in 1873 along with famous Colt M1873 Single Action Army revolver, and was adopted by US military. Originally a strictly blackpowder loading, today this round can be found in both blackpowder versions (for old revolvers) and in smokeless loadings for modern revolvers and carbines.
The alternate (and unofficial) designation .45 Long Colt (or .45LC in short) comes from relatively recent times, to distinguish it from another .45 caliber military revolver loading of the 1875 era, the .45 Shofield, which featured shorter case and lighter charge.