Originally Posted by Captain Kidd

Yes, that does seem to be one of the golden rules of Hollywood. Drawing a weapon, or just pointing one at someone/something, causes it to make that cocking sound. It'll do it, even if you can plainly see that the wielder's hand/hands never leave the grip.

Of course only pump action shotguns are allowed, and they have to have the rounds continuously chambered too. There was one movie I watched where the guy pointed it and pumped it. The other person ducked around a corner so the first guy runs around it and pumps it again. I can't remember how many times this happened, but by the time that scene was over there was no way there were any shells left in the gun. Unless this is some sort of advanced shotgun that unloads back into the magazine if you don't fire in X amount of time.