3D Printed Guns Pose New Threat

WASHINGTON -- When a decades-old law banning undetectable firearms expires less than a month from now, federal agents say a plastic weapon created on a 3-D printer could emerge as a national security threat. The homemade plastic gun, known as the "Liberator .380" and made with a computer blueprint, a 3-D printer and plastic resin, could pass through security checkpoints without setting off metal detectors. The gun uses only the smallest bits of metal for ammunition and a firing pin the size of a roofing nail. The Undetectable Firearms Act, passed in 1988 and renewed in 1998 and 2003, expires at midnight Dec. 9. The law, which envisioned gun manufacturers using more plastic as technologies improved, requires guns to have enough steel to set off a metal detector.