They say there have been many double barreled guns in the past, which of course is true, but the purpose has always been to have multiple shots available, either in leiu of a repeater (before there was any such thing as a repeater) or to have a second shot on hand without working an action, usually in a large African caliber or a shotgun. In this case both barrels fire together. It’s an interesting novelty. Maybe you could fiber/epoxy a couple of 1911s together and have a similar experience. The variations on the jam, or other stoppage, should be interesting as well. The two barrels are serviced by a common slide.