Initially confused with a Model 1873 Sheriff's and Storekeeper's Model, the revolver used by both Vienna and Emma is a Model 1877 Colt "Thunderer". Note the slimmer profile, rounded front sight, larger trigger guard, and milled step in the frame just forward of the trigger guard. The 1877 also has longer cylinder flutes because there are no notches for lockup (lockup is at the rear of the cylinder). Rather uncommon in Westerns, the smaller birdshead grip and double-action are better suited to a woman's hand, although Vienna's revolver has been modified with a plowhandle grip to give it a greater resemblance to the Single Action Army (lobby cards for this movie depict Joan Crawford with a holstered gun that clearly has a double-action trigger combined with a SAA-type grip frame; such an item may have been cobbled up for Ms. Crawford or it may have been something the firearms rental company carried in stock).
Some characters are armed with Winchester Model 1892 rifles. While it may seem that Hollywood and even the Italians created a world where men only carried Single Action Armys and Model 1892 rifles (rather anachronistic), much of this is driven by the fact that the SAA was manufactured until 1940-41 and the Model 1892 until 1945. Studios were able to make movies without depending on museum pieces and these firearms were able to fire the popular 5 in 1 Remington Blank which is still being manufactured, now with a plastic case.
