And this is also a western that takes place in the era of the machine gun! A key plot point (Spoilers) involved the gang, led by Pike Bishop (William Holden), robbing a railroad office while dressed as U.S. Army soldiers, and later robbing a weapons shipment from a U.S. Army train. In the process, the gang steals a .30-06 water-cooled Browning M1917 machine gun. This is an anachronism as the gun, denoted by its military designation of M1917, wasn't developed yet in 1913 when the movie takes place. But the Maxim Machine Gun and similar models like the Colt M1895 had been around for a couple decades already, so the presence of a machine gun isn't far fetched.