Ian, you are into films, there's one I can't find . . . . not helped by the fact I can't remember the title
Comedy western with Jack Elam, he's the leader of the most inept gang of bandits you'll ever come across. In one scene they are practicing a bank robbery, a rock represents the safe. One of the bandits puts a stick of dynamite next to the rock to simulate blowing the safe but actually lights the fuse and it explodes right next to Jack Elam. In the next scene he's deaf, bandit on his left speaks to him, he turns and answers the one on his right
Its not "Support your local sheriff" or "Support your local gunfighter". I've tried looking at lists of Jack Elam films and nothing rings a bell, any suggestions