In this weapon mod, the chamber of a 12 gauge shotgun, a hammer from an 1857 Remington Perc Revolver, and other parts from an Italian auto shotgun were all combined to make this happen.

Types of shotguns are ... the pump-action Remington 870 and Mossberg 500, which have sold over 10,000,000 units collectively. When it comes to shotgun gauges, the 12-gauge is the most common ...