This is a box I made hold the parts for my Desert Tech MDRx caliber conversion kit. This should work with all caliber kits however I have only tested it with the .223 and .308 kits. Additionally there is a slot for a plastic punch tool. Parts of the this are remixed from "Max's 50 round 9mm ammo box" which I believe is no longer on Thingiverse. The fit between the lid and box is tight at first but with some slight filing or repeated sliding on/off it will work smoothly.

I will try and add a version without the punch tool and may make occasional tweaks as needed.