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 for which they were chambered: for the "Thunderer", .41 Long Colt; for the "Lightning", .38 Long Colt; and for the "Rainmaker", .32 Long Colt. All of the models had a six-round capacity.