A shotgun with two barrels, two bullets, and has more stopping power then a desert eagle on 'roids. When fired, you can reload one bullet, or fire both and reload both. Simply a matter of preference. Also has incredible recoil if your not careful, and it can AND WILL break your arm/shoulder/face.
Guy 1: Hey, lets fire this double-barrel shotgun with one hand!
*fires*
Guy 1: Shit, I think I broke my arm!
Somatotype Shotgun is the situation that regardless of who calls shotgun in the vehicle to be used, someone automatically gets the shotgun due to their girth or height etc, for convenience.