Factual errors: The guns being used belong to the period from about 1870 to 1880. If this film was set during the California gold rush period of 1849 the weapons should all be percussion cap and black powder. Repeating rifles weren't developed until late in the civil war.
Factual errors: The film is set in Mexico and the Indians are being called Apaches. However, they are dressed as Northeastern American Mohawks. In addition, the men of the Apache nations were traditionally long-haired. In this film, the "Apache" Indians are sporting Northeastern Mohawk haircuts.