Since President Clinton, powers have been aquired by the Office of Presidency that have not been used yet by any President. Not so sure anymore pyromancer.Executive orders general have to be backed by the constitution or some other federal law. If the president chose to do this it could easily result in a supreme court case, and I am sure the NRA or someone else would jump at the chance to take the President to the supreme court .
Executive order - Wikipedia, the free encyclopedia
"Until 1952, there were no rules or guidelines outlining what the president could or could not do through an executive order. However, the Supreme Court ruled in Youngstown Sheet & Tube Co. v. Sawyer, 343 US 579 (1952) that Executive Order 10340 from President Harry S. Truman placing all steel mills in the country under federal control was invalid because it attempted to make law, rather than clarify or act to further a law put forth by the Congress or the Constitution. Presidents since this decision have generally been careful to cite which specific laws they are acting under when issuing new executive orders."