Factual error: The action in this movie takes place in 1869, yet half of the handguns are 1873 Colt Peacemakers, and the remainder that are Army or Navy Colts are all cartridge conversions, which were not available until 1871.
Factual error: The movie takes place in 1850-51, and yet when the Rabbi is challenged to a shootout in San Francisco, the weapon he is handed is an 1858 Remington New Model Army revolver.