I am currently printing this, so cannot completely confirm its functionality!
This is designed to hold 25 12 gauge shells, bottom up, while the bottom of the piece itself accepts the rimmed end of the shell, allowing for stack-ability. These are designed to fit end to end in a 50 cal ammo can, allowing for storage of 100 shells in 4 of these holders.
12GAshellHolder.stl | 1.1MB |