On Special Report tonight, Doug McKelway took a look at the growing concern over ammunition shortages in the country, particularly the Department of Homeland Security's purchases of mass quantities of ammo.

Sen. Tom Coburn (R-Okla.) says he has been hearing about this more and more from his constituents and, along with a dozen of his colleagues, has written to Homeland Security Secretary Janet Napolitano about the issue. One of the letters asked why the government is stockpiling "considerably more (ammunition) than historical

use would suggest is needed."

The purchases are fueling long-held conspiracy theories on the internet, with people arguing that the government is trying to confiscate ammunition as a form of gun control or preparing for some sort of domestic conflict.

But Coburn says that if you go through the DHS purchases "without fear" it appears the government is "doing exactly what they need to do." DHS points out that 148 million rounds of ammo were purchased in 2010, with that number going down to 108 million in 2011 and 103 million in 2012.

Watch the full report: