This is the same as the 556 20-round ammo case but for 100-rounds. this has not been printed or tested yet. If you download it and print it let me know how it works. I will get to printing and testing soon.
I was able to print this out and have the lid fit good. But I did have a printing issue where my sides were not solid, they were single sheets of plastic. It holds my ammo just fine, just need to figure out why the walls were not solid. The 20-round ammo cases had solid walls. If you do print this out please let me know how it printed for you.