Just as gun control has made a comeback among politicians after a spate of deadly mass shootings, the rapid advances in 3-D printed guns have threatened to undermine those controls before they even get started. According to a leading 3-D printing researcher, the only way to prevent printed guns from shooting a new loophole in the law may be to control the gunpowder you need to fire them.

‘Perhaps the only way forward, if we choose to try and control this, is to control the gunpowder - the explosives - and not the actual device,