The Bullet That Could Make 3-D Printed Guns Practical Deadly Weapons

"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."