FOX 26 - Mechanical engineering student James Patrick recently uploaded a YouTube video showing a fully functional PM522 Washbear .22LR revolver that he designed and 3D printed. It's a 3D-printed pepperbox revolver capable of firing up to 8 bullets between reloads. Except for an elastic band spring, a metal firing pin, and steel rods as detectable metal, the gun is entirely 3D-printed using ABS plastic or a durable nylon material. According to Patrick, it is the world's first functional 3D-printed repeating firearm that has been printed using a consumer 3D printer.
Here is a video of the Fully functional PM522 Washbear .22LR revolver in action.