Years ago a story was told of a man who had a Model 12 trap gun that was so worn there was a pinhole at the end of the barrel. When he shot, a little puff of smoke came up out of the hole. Everyone figured there couldn't be any choke left in that barrel, but he believed in the gun and he broke targets with it. Finally when the gun was in to be repaired for something else, the gun smith welded up the little hole. When the gun was given back to the man, he said he's kind of missed the little puff of smoke.