Shotgun Basics: Identifying parts and functions | Tactical Experts | TacticalGear.com
Amazon.com : Seneca Double-Shot .50-Caliber Double-Barrel Shotgun Air Rifle, PCP Air Rifle : Sports & Outdoors
Johann Fanzoj Vierling: Four-Barreled Rifle-Shotgun -The Firearm Blog
I keep seeing three-barrel over-under guns with a rifle barrel and two shotgun barrels, but I can't seem to find these online. Where should I look for more information? - Quora
Firearms Facts Episode 10: "Shotshells from Rifled Barrels" - YouTube