Patzer

Due to stringent gun control laws, movie prop departments in Spain face extraordinary difficulties obtaining period-appropriate weapons. In the first scene, in which a train is attacked in Barcelona in 1921, the firearms displayed by both sides are implausible and/or wildly anachronistic:

• M1 Garand rifle. Designed in 1936.
• M1 carbine. Designed in 1941.
• Sten sub-machine gun. Designed in 1941.
• MP 40 sub-machine gun. Designed in 1938.
• Lee Enfield rifle. While they existed in 1921, they were never in service in any Spanish law enforcement agency or the military, who were issued the ubiquitous Mauser bolt rifles and carbines.
• Thompson sub-machine gun. While they existed in 1921 (having been designed in 1918), they would have been unheard of in Spain, as they entered production that year and were sold in small quantities to some federal and Law enforcement agencies in the US, the Marines and some armies in Latin America.

Not only that, the defenders of the train, presumably military, display the above collection of firearms (except for the sub-machine guns, carried by the attackers), implausible for any uniformed body, who would have been issued the same model of rifle (in Spain, the Mauser family of rifles and carbines).

Salvador Ortiz, the leader of the anarchist strikers, tells the boss Don Emilio that the strikes will end when the workers are no longer forced to work over 10 hours. The eight-hours-working day though was a result of the Huelga de La Canadiense, a strike lead by CNT, in 1919 in Barcelona and came into action by a government decree. The movie is set in 1921.

Looks like in the movie Sara uses a Walther PP (German: Polizeipistole, or police pistol). This pistols were designed by the German arms manufacturer Carl Walther GmbH Sportwaffen in 1929 and the movie was set in 1921.