We called this article Shotgun Shells 101 because it's your entry-level look at everything that makes up a shotgun shell, the types of shells and more.
The DP-12 Shotgun: A Wild Design That Works
Your guide to Georgia's gun laws - Atlanta Civic Circle
8 Ways To Reduce Gun Violence in Minnesota - Center for American Progress
Calibers & Bullets 101
GUNS Magazine Cowboy Action Shooting 101 - GUNS Magazine
What About 20 Gauge for Home Defense? - Lucky Gunner Lounge
Shotshells 101 An Official Journal Of The NRA
How to Use a Pump-Action Shotgun - Lucky Gunner Lounge
12-Gauge Mini Shells from Federal, Aguila, and Nobel - Gun Tests
Cruiser Ready: How to Store A Home Defense Shotgun