The Colt M1877 was a double-action revolver manufactured by Colt's Patent Fire Arms from January 1877 until 1909 for a total of 166,849 revolvers. The Model 1877 was offered in three calibers, which lent them three unofficial names: the "Thunderer", the "Lightning", and the "Rainmaker". The principal difference between the models was the cartridge in which they were chambered for, these are the "Thunderer" in .41 Long Colt; the "Lightning" in .38 Long Colt; and the "Rainmaker" in .32 Long Colt. All of the models had a six-round capacity.

Colt's Manufacturing Company, LLC is an American firearms manufacturer, founded in 1855 by Samuel Colt and now a subsidiary of Czech holding company Colt CZ Group. It is the successor corporation to Colt's earlier firearms-making efforts, which started in 1836. Colt is known for the engineering, production, and marketing of firearms, most especially between the 1850s and World War I, when it was a dominating force in its industry and a seminal influence on manufacturing technology. Colt's earliest designs played a major role in the popularization of the revolver and the shift away from single-shot pistols. Although Samuel Colt did not invent the revolver concept, his designs resulted in the first very successful model.