If ammunition does become the focus for gun owners, that could become another hot-button topic.
Last year, the Homeland Security Department had to explain to Congress its contracts to buy up to 1.6 billion rounds of ammunition.
Some gun owners believed the department was trying to crowd out private consumers in the ammunition market, but federal officials said their purchases amounted to a tiny fraction of the ammunition produced every year.
The national background checks have been part of the Newtown debate.
Only federally licensed dealers are required to check customers through the system, but Sens. Joe Manchin III, West Virginia Democrat, and Patrick J. Toomey, Pennsylvania Republican, proposed expanding the mandate to include many private transactions. That plan failed to clear the Senate.
The Obama also took steps, including two last week designed to encourage states to post more data about mentally ill residents to the national system.
The Department of Justice is moving to clarify who is prohibited from having a gun because of mental health issues, and the Department of Health and Human Services is proposing a regulation to help states submit more information on such people to the national background check system.
The administration says some states have indicated that federal privacy provisions might be preventing them from submitting information about people who cannot legally buy guns because of mental health issues. HHS now is proposing a rule to give certain entities express permission to disclose identities to the national background check system to keep such people from buying guns.