The problem with shooting most 3D printed guns is that they tend to blow up. The extruded plastic components can’t take the strain caused by the expanding gasses of the powder charge, and so the gun delaminates and breaks apart. One enterprising young man from Pennsylvania thinks that he has the problem licked. His solution: specially-designed ammunition . . .
From Wired:
Michael Crumling, a 25-year-old machinist from York, Pennsylvania, has developed a round designed specifically to be fired from 3-D printed guns. His ammunition uses a thicker steel shell with a lead bullet inserted an inch inside, deep enough that the shell can contain the explosion of the round’s gunpowder instead of transferring that force to the plastic body or barrel of the gun. Crumling says that allows a home-printed firearm made from even the cheapest materials to be fired again and again without cracking or deformation. And while his design isn’t easily replicated because the rounds must be individually machined for now, it may represent another step towards durable, practical, printed guns—even semi-automatic ones.
Michael’s brainstorm is to rely on the metal of the ammunition’s case to contain the gasses instead of the surrounding material of the gun’s chamber. It’s a nifty idea, and seems to solve most of the problems that plastic 3D-printed gun makers are facing with their designs.
Essentially the ammo becomes a self-contained unit capable of doing all the work of actually forcing the bullet forward. All the gun would have to do is aim the cartridge and set off the primer. Taken a step further, someone might start producing a round such as this with a longer case length and perhaps even some rifling, producing a drop-in chamber, barrel and projectile all in one package. That should make the ATF happy, no?
Life, uh, finds a way.