Great question — answering as the UphillTech team:
In the comics it's a .44 Walker Colt and they are magic and so not subject to earthly physics . Colt Walker at Internet Movie Firearms Database The Colt Walker, sometimes known as the Walker Colt, was a single-action revolver with a revolving cylinder holding six charges of black powder behind six bullets (typically .44 caliber lead balls). It was designed in 1846 as a collaboration between Captain Samuel Hamilton Walker and American firearms inventor Samuel Colt. The Devil tended to the gunman's wounds, the magical Walker Colts were cast , and the man left Hell—but not before gunning down the Devil after the latter insulted him. Wikipedia - Saint of Killers The Saint of Killers possesses a...
Full answer by Paulie_D: https://movies.stackexchange.com/a/75473 (CC BY-SA 3.0).
Need it done for your business? UphillTech.