http://www.fas.org/sgp/crs/misc/R42987.pdf

Summary
Congress has debated the efficacy and constitutionality of federal regulation of firearms and ammunition, with strong advocates arguing for and against greater gun control. The mass shooting in Newtown, CT, along with other mass shootings in Aurora, CO, and Tucson, AZ, has restarted the national gun control debate. Members of the 113th Congress could consider a range of legislative proposals, including several that President Barack Obama has announced his support for as part of his national gun violence reduction plan. The most salient of the President’s legislative proposals would (1) require background checks for intrastate firearms transfers between unlicensed persons at gun shows and nearly any other venue, otherwise known as the “universal background checks” proposal; (2) increase penalties for gun trafficking; and (3)
reinstate and strengthen an expired federal ban on detachable ammunition magazines of over 10-round capacity and certain “military style” firearms commonly described as “semiautomatic assault weapons,” which are designed to accept such magazines.

On March 21, 2013, Senator Harry Reid introduced the Safe Communities, Safe Schools Act of 2013 (S. 649). As introduced, this bill included the language of several bills previously reported by the Senate Committee on the Judiciary. Those bills included the Stop Illegal Trafficking in Firearms Act of 2013 (S. 54), the Fix Gun Checks Act of 2013 (S. 374), and the School Safety Enhancements Act of 2013 (S. 146). However, the Assault Weapons Ban of 2013 (S. 150) was not included in S. 649. From April 17-18, 2013, the Senate considered S. 649 and nine amendments that addressed a wide array of gun control issues, ranging from universal background checks to assault weapons. By unanimous consent, the Senate agreed that adoption of these amendments would require a 60-vote threshold. All but two of these amendments were rejected. However, a
final vote was not taken on S. 649. This report provides an overview of federal firearms law and examines these gun control proposals and related amendments. While the House has not considered any of the gun control proposals debated in the Senate, on May 8, 2013, the House Committee on Veterans’ Affairs approved a bill, the Veterans 2nd Amendment Protection Act (H.R. 602), that addresses veterans, mental incompetency, and firearms eligibility.