The old railway seen in this movie was also used in the movies Red Sun (1971), The Long Duel (1967) and North West Frontier (1959).
So, you want to play games, do you? Do you know the one we've got called whip-the-truth-out-of-a-prisoner?
During the gunfight on the hillside, the two brothers randomly fire off rounds, or at least they cock their pistols and pull the trigger each time, and a pistol shot sound is heard. However, the guns don't kick and there is no smoke from the fired cartridges, so they aren't even firing blanks. They are just pulling the trigger on unloaded chambers.
German theatrical version was cut by ca. 7 minutes.