Ah heck!
I wish I had a dollar for all the times the Hollywood studios substituted firearms that were easier to operate than the real thing.
Did you ever see the scene in Winchester '73 where Lin shoots Waco Johnny Dean? In his death throes Waco (Dan Duryea) fires his revolver rapidly into the ground. This was clearly done with a modern double action revolver, who could cock and fire a single action revolver rapidly while he was dying?
Earlier in the film Charles Drake, as Steve Miller proudly proclaims he is holding a Henry rifle when it is clearly a Winchester Model 1873 in his hands.
And when Dutch Henry Brown complains about Henry rifles not having any killing power, he is also holding a Winchester Model 1873 in his hands.
In The Man Who Shot Liberty Valence, James Stewart is holding a double action revolver that the prop department had cobbled an ejector housing onto to make it look somewhat like a SAA.
Have you ever heard of a 'Hollywood Henry'? A Winchester Model 1892 with the fore arm removed to make it resemble a Henry. There was one in the shooting match scene in Winchester '73, and Burt Lancaster carried one all through The Scalphunters.
The Walker Colt Augustus McRae carried in Lonesome Dove was a modern Italian replica modified to shoot 38 Special blanks.
I could go on and on. Did you know it was common for the prop departments to take antique Trapdoor rifles, saw them off to look like a pistol, put a fake flintlock pan on them and pass them off as flintlock pistols in pirate movies? Much quicker to reload a Trapdoor with a blank than to bother with flint.
The fact that the producers of Shane substituted modern revolvers in a shootout just emphasizes my point that Jack Palance was not very good with guns. Alan Ladd hated guns and was not very good with them. In one scene Shane shoots somebody even though his revolver is clearly not pointing at the victim.
Anyway, just a publicity photo, but that is clearly not a Colt Police Positive.
These are Colt Police Positives. To be more accurate, they are Police Positive Specials, meaning the cylinders are long enough for 38 Special ammunition. Except for the little 22 Police Positive Target on the far right.