This is an ammo box for the 7.62x39 cartridge.
After printing 6.5 Creedmoor by passatiji, I really liked the box! It's not just a ammo box: it is extremely useful on the reloading bench as well as at the range. When reloading, the base can be used as a tray. At the range, the base is used to stage cartridges, and the cover is used to store spent cartridges.
After using it for a while, I decided to design a similar case for other calibers. Several changes were made to the original I believe are improvements :

• The box is 5 rounds wide and 10 rounds long for exactly 50 cartridges. This makes it easy to count rounds. Need to load a 20-round mag? Just grab two long rows! Want to run a string of 5 shots at the range? Pick up all rounds on the short side of the case!
• Optimized printing speed. The walls of the box are exactly two nozzle widths wide. If you set the wall thickness count to 2, the print will print 50% faster than the original. The box is less rigid but still is very rugged. The Hexagonal shapes make for very rigid structures already!
• Re-created the box in OnShape parametric CAD software. The benefit of Onshape is that it allows one to resize the box for any necked cartridge just by providing a few SAAMI measures and the box is automatically resized. The drawing is available to anyone with an OnShape account: 50rd Ammo box

If you need another necked cartridge made, drop me a note and I'll generate one