.50 BMG threaded cartridge like the Barrett uses! 1:1 scale.

I looked at the other designs of these cartridge containers. I noticed some of them were missing features, or were not entirely hollow and didn't maximize the available space inside (particularly inside the projectile). This one was made from blueprints that I could find with as much detail as was available. I printed with eSun copper, Polymaker PLA+ metallic gold, and eSun blue. It can be printed without supports. It also has a headstamp and primer on the bottom which many other models lack.

I took extra time to get the threads working well and printing without supports. They thread together well, a little bar of soap rubbed on the threads will make it extremely smooth.