Iver Johnson Stryker SN 12gauge Pistol
The Iver Johnson Stryker is a 12-gauge semi-automatic shotgun often marketed for tactical or home defense purposes. While you referred to it as a "pistol," it is categorized as a shotgun due to its 12-gauge barrel, which is designed to fire shotgun shells rather than handgun rounds. It may, however, have a more compact or pistol-like grip, which might contribute to some confusion.