"Democrats say 3-D printers that can produce plastic guns make tighter restrictions necessary."
Congress has approved a 10-year extension of a ban on plastic firearms that can evade metal detectors and X-ray machines. But it has defeated gun-control advocates' push for tougher restrictions.
The Senate used a voice vote Monday to renew the ban. The House did the same last week, so it now goes to President Barack Obama for his signature.
Republicans blocked a proposal by New York Democratic Sen. Chuck Schumer. He wanted to require that plastic guns have an undetachable part made of metal.
Some plastic guns follow the law by including a metal piece that can be detached.
Democrats say 3-D printers that can produce plastic guns make tighter restrictions necessary. Republicans say Schumer's idea should be studied.
Unless Congress acted, the prohibition would have expired at midnight.