How Does Ultrakill's Shotgun Work?

How does ultrakill's shotgun work? I will try to see how it works and if we could make it in real life with engineering.

Music Used:
Terraformer - Rimworld
Seasons turn - Rimworld
Shadow Work - Rimworld
Space Town Dub - Everhood

I am more or less new to content creation so expect a lot of mistakes, constructive criticism is very welcome. (don't be mean about it though)

Recorder: OBS
Editor: Flow Blade
Patreon: patreon.com/AlchemicalRaven