This was made so I could reuse cheap shotgun shells to make 12 gauge shotgun snap caps. I found some 3D models but nothing that fit. It was designed using Federal Top Gun 2 ¾" shells
I printed in ABS and PETG, both with 35% fill and 4 walls.
I use a Lee Load-All reloading press to prep/deprime the shells. Load this insert on the middle (wad) station and make sure it is fully seated before proceeding to crimp as normal.
A friend of mine even added a drop of silicone to the primer pocket to make it more flush and give a buffer between the firing pin and plastic.
These can be used for function checks, dry fire and to simulate jams. They should cycle exactly like their retail counterpart.
*I only have high brass on hand for comparison.
The author marked this model as their own original creation.