in this six minute video you will discover that there are double barreled magazine extended clips described by a retired female la police sargent.

and there are more:

• High Magazine Clips And The Shoulder Thing That Goes Up
• The Captain’s Journal » High Ammo Clips
• The Captain’s Journal » Automatic Bullets In Rapid-Fire Magazine Clips
• The Captain’s Journal » Duck Hunting With Bullets
• The Captain’s Journal » Guns, Accoutrements And Idiots
• The Captain’s Journal » The Fully Loaded Ammunition Cartridge
• The Captain’s Journal » The High Magazine Round
• The Captain’s Journal » Mother Jones On “High-Caliber Rifles”
• The Captain’s Journal » The 40-Clip Magazine

https://youtu.be/ms8UXjPVJpg