A guy on another forum I use made one he called the frankengun. I think it was a ruger vaquero originally, but he tapped a gas port into the barrel and uses the gas to eject the brass. Then he had to add a shield to keep the brass from killing him. Then he created a magazine that would feed live rounds into empty chambers giving him either 4 or 6 extra shots (2 different sized mag tubes). Wish I could find a picture or the video. It was a hell of a feat.