This is a quad (and twin) loading shell holder for the Spring Thunder by GDop26. It's designed to fit on molle, and allows you to twin load two shells at a
...Show more time, reducing reloading speed, but also giving a solid platform to carry a lot of shells.
I'm not sure about printer compatibility, but it should be easy enough to print on a prusa sized printer.
There is also a good chance that these will go up on GDop's shop on etsy, so if you can't print them you can still buy them.
https://www.thingiverse.com/thing:2846629/#files
https://www.etsy.com/shop/ShellEjectingBlaster?ref=seller-platform-mcnav
