Bullets are speeding faster out of gun shops in U.S.

But the spike under Obama seems to be on a different scale: The receipts are on pace to set a record in 2009, according to Treasury Department data, with tax revenue due from guns up 42 percent and revenue due from ammunition at 49 percent. Recently, analysts have said earnings reports from gunmakers seem to show demand for weapons slackening.

The increase in gun buying during the past year explains a large part of the increase in ammunition sales to the private market, experts on the industry say -- but probably not all of it.

They say that bullets were bought not just by new gun owners but also by those who already owned weapons. And they say bullet sales might have increased even faster if supply had kept up with demand.

Bullet makers say the reasons for these shortages include the wars in Iraq and Afghanistan, which have made bullet components such as copper and brass more expensive.

For gun owners in the Washington area and elsewhere, the run on ammunition has created shortages and price increases on everything from cheap .22-caliber bullets used for target shooting to the expensive hollow-point 9mm rounds bought for home defense.

In Maryland and Virginia, as in many states, anyone over 21 can buy an unlimited amount of ammunition without a special license or background check. The District has tighter rules for its one licensed ammunition dealer: Gun owners can buy bullets only in the same caliber as their registered guns.

Reason for alarm?

The high sales have alarmed some anti-gun groups. Josh Sugarmann of the Violence Policy Center said he worries about a revival of the anti-government militia movement of the Clinton era.

"This is a pattern that is repeating itself, and it is a pattern that has tremendous risk attached to it," Sugarmann said.

But gun-rights groups say the buyers are law-abiding, and responding to legitimate concerns.

"I think it's Katrina. I think it's terrorism. I think it's crime. And I also think that it's people worrying about [whether] they'll be attacked by politicians," said Wayne LaPierre, executive vice president of the National Rifle Association. "They're suspicious, and justifiably so."

But the most recent FBI crime statistics, from 2008, showed that rates of violent crime were the lowest since 1989. The numbers for this year have not been assembled yet, but police groups say violent crime still appears to be down, although there may have been an uptick in property crimes.

As for gun control, experts say that far from being under attack, groups opposed to it have won a remarkable string of victories. Clinton's ban on assault weapons expired in 2004. The U.S. Supreme Court struck down the District's restrictions on handguns, ruling that the Second Amendment creates an individual right to gun ownership.

Under Obama, the White House has said it wants to stop the illegal flow of U.S. guns to Mexican drug cartels, and it directed Attorney General Eric H. Holder Jr. to review the way current gun laws are being enforced.

But a spokesman said that "the president respects and supports the Second Amendment and the tradition of gun ownership in this country." In the biggest gun-related debate of his tenure, Obama sided with gun groups, signing a bill to loosen the rules on firearms in national parks.

Still, in interviews with gun owners and ammunition dealers, many said the run on bullets was sparked by worries about what Obama might do.

"It was just logical, based on his record as a state senator and his record in the U.S. Senate," Dave Sugg, 37, a consultant in Ashburn, said after taking target practice with a .22-caliber semi-automatic Ruger rifle at a shooting range.

Research director Lucy Shackelford contributed to this report.