1, Point in a safe direction, unless you are filming a gun fight per the Directors instructions.
2. Always treat a gun like it's loaded, meaning no fake shots in a movie.
3. Keep your finger off the trigger, Especially a modified Peacemaker, or a Sig.
4. Be sure of your target, like an expensive movie camera with a real person sitting behind the camera.
Seems the only way for a prop gun to be handed over safely is to hand it over UNLOADED and the next person verify all chambers are empty. When handed to the actor, load required dummies, rattle rounds, and blanks in view of the final set of hands.
That probably applies to semi autos used in films and all magazines as well.
Empty mags loaded at the last minute, by the actor, not left lying around.
Might have a live round in one of the mags.