A new 3D-printed insert for a 22LR ammo case now fits 297 cartridges inside the same outer box. Its maker rejected an earlier tray because the openings gripped each round too firmly and left unused gaps between them. The revised layout packs more ammunition while simplifying loading and unloading, and it requires less plastic and less printer time.

The denser arrangement makes individual rounds a bit more awkward to lift out. A later file may raise every other row to ease that grip, and the designer plans to share it after a test print.