Indiana used a WG webley in the movies.
He actually carried more than one kind of model:
Indy's pistol - Indiana Jones Wiki - Raiders of the Lost Ark, Temple of Doom, Last Crusade, Kingdom of the Crystal Skull, Young Indy, and more!
I was referring more to the model he used in LC and CS. It was a WG not a MK 4 or 6. I keep seeing people passing that info about the gun even after it has been refuted. All you have to do is look at freeze frames of the DVD. And prop store of London owns the LC gun. They have PICS.