Along with "splitting Oreos," "shooting odd stuff out of shotguns" is now a YouTube sub-genre. In this clip it's dimes and pounded pellets. Others have bits of wire, hot dogs (seriously), washers, .22 pellets, and almost anything else you can fit in a 12 gauge hull. Don't try this at home. Let other people try it at their homes and watch the results instead. It's safer. These particular guys seem to sort of know what they are doing, but, to no one's surprise, many YouTube reloaders do not.