The UK Home Office has added language to its firearms rules, making clear that it's generally illegal to make, own, or sell 3D-printed guns. A revised version of its licensing policies says that guns like the Liberator, designed by Defense Distributed and released to the world in May, are covered under and forbidden by the Firearms Act 1968 — manufacturing 3D-printed guns or parts is effectively already banned because of rules against manufacturing guns or gun parts except under certain exemptions, but the guidance now includes explicit text to that effect. "3D printed weapons are potentially lethal barreled weapons and must be viewed as such in law," it reads. "The method of manufacture is not material to this consideration."

In a section of frequently asked questions, regulators say they're still working through the wider implications. "If someone were to possess, purchase, manufacture or sell a firearm or its component parts otherwise than in accordance with the requirements of sections 1, 3 and 5 of the Firearms Act 1968, they would be liable to prosecution," the guidance says. "We are working closely with our partners, including the police and firearms experts, to assess other implications." So far, the change is more symbolic, a pushback against Defense Distributed's assertion that affordable printers will make gun control impractical. "3D-printed guns were illegal before and are still illegal, but we felt it was appropriate to have specifically refer to them in our firearms licensing guide," said a spokesperson for the UK Home Office.

The UK's decision to add language about 3D-printed guns contrasts with that of US lawmakers, who recently renewed the "undetectable guns" law that requires a certain amount of metal in any firearm. While Senator Chuck Schumer (D-NY) promoted his renewal bill by discussing printed guns, the House version of the bill made no changes to the old law and no mention of 3D printing. Schumer has since warned that the House bill doesn't go far enough, leaving a dangerous loophole. "Under current law, it is legal to make a plastic gun so long as it has some metal in it, even if it is easily removable," he said in a statement earlier this week. "The bill we'll try to pass in the Senate would fix that."