AURORA, Colo. -- A powerful sense of fear that gun control is inevitable appears to be the driving force behind a run on ammunition resulting in a national shortage.

"We're probably selling ammunition right now at a 200 percent increase over normal sales," said Richard Taylor, manager at the Firing Line in Aurora. He calls it "panic buying".

Ammunition including 9-millimeter, .40 caliber and .45 caliber shells are the hardest to find and the most popular with handguns used for self-defense.

"Just about everywhere I've been it's sold out. Wal-Mart, Sportsman's wherever," said Darren Lauzon who brought his family and his own, older shells for his brand new .45. "I kind of don't believe that it will vanish. I don't think it's wholeheartedly rational, but I can see why people are concerned."

Soon after President Barack Obama was elected in November, new gun purchases jumped.

Now, with government taking large ownership stakes in private companies to shore up the economy, some gun owners said more government control -- or increased taxes -- will follow.

"Well everybody's just worried about the new government coming in and trying to ban guns and make everything more difficult to obtain," said Kevin Bishop, and Aurora resident and NRA member. "Well the way he's been acting there may be a little truth to the rumor."

But it appears the worry is based solely on rumor.

State lawmakers have not attempted to tax or further control gun sales.

In Washington, there has been talk of banning assault weapons again, as happened under President Bill Clinton.

But Democratic lawmakers recently stated they would oppose any such bill.

Even the president of the Colorado State Shooting Association, closely aligned with the NRA, couldn't pinpoint one exact reason for the ammunition shortage or the increase in NRA membership.

Tony Fabian said a combination of factors are at work, including the fear factor, to cause the ammo run.

The rising costs of metals, heavy usage by the U.S. military still at war in two countries, and new gun owners from late 2008 now realize they need more rounds are all contributors.

The impact is undeniable at the gun shop.

"We've probably got over 4,000 cases of ammunition on back order currently. But we just don't know when we're going to receive that," Taylor said. "Y2K was just like a little blip on the radar screen compared to this. I mean, it's just phenomenal."

On the NRA's Web site, one of the front page entries is a vote expected Tuesday by city council in Long Beach, CA that could require gun shop vendors to obtain information from ammunition buyers.