In the Raven Bar shootout in Raiders, if you look carefully you'll notice that Indy is using two different types of pistol. One is his trusty revolver, but the other is a different, clip-loaded pistol. Additionally, if you watch the quick cuts, in some of the close-ups he's clearly using the wrong gun at the wrong time (i.e. wide-shot of Indy holding the revolver, then quick close-up of Indy firing the other pistol, then back to wide shot of him holding the revolver.) I just noticed this for the first time while watching it the other night.