This is the world's first 3D printed replica of a .22 Magnum cartridge, that I designed for a friend's project. It has the same exact specs as a real .22 magnum, so you might be able to use it as a snap cap for safely dry-firing your firearm, but I haven't tested them for that. I also added a .step file so that you can modify it, too.I printed it out of blue PLA with .2mm layer heights on Spiral Vase mode. I think that printing it hollow with multiple perimeters(shells), to maintain accuracy and strength, would also work well.