The 1871 Colt Open Top Revolvers were produced simultaneously with the Richards and Richards-Mason Conversion. Between February 1872 and June 1873, a total of 7,000 pieces were produced. This Colt revolver is not a conversion but was produced for metallic cartridges: the barrel, cylinder and frame were made intentionally, whereas parts such as the grip assembly and the internal components were adapted from the Navy `51 and the Army `60. Production stopped abruptly when the Single Action was introduced