(Photo: Michael Saechang / Flickr)As Washington focuses on what Vice President Joseph R. Biden Jr. will propose next week to curb gun violence, gun and ammunition sales are spiking in the rest of the country as people rush to expand their arsenals in advance of any restrictions that might be imposed.

People were crowded five deep at the tiny counter of a gun shop near Atlanta, where a pastor from Knoxville, Tenn., was among the customers who showed up in person after the store’s Web site halted sales because of low inventory. Emptying gun cases and bare shelves gave a picked-over feel to gun stores in many states. High-capacity magazines, which some state and federal officials want to ban or restrict, were selling briskly across the country: one Iowa dealer said that 30-round magazines were fetching five times what they sold for just weeks ago.

Gun dealers and buyers alike said that the rapid growth in gun sales — which began climbing significantly after President Obama’s re-election and soared after the Dec. 14 shooting at a school in Newtown, Conn., prompted him to call for new gun laws — shows little sign of abating.

December set a record for the criminal background checks performed before many gun purchases, a strong indication of a big increase in sales, according to an analysis of federal data by the National Shooting Sports Foundation, a gun industry trade group. Adjusting the federal data to try to weed out background checks that were unrelated to firearms sales, the group reported that 2.2 million background checks were performed last month, an increase of 58.6 percent over the same period in 2011. Some gun dealers said in interviews that they had never seen such demand.

“If I had 1,000 AR-15s I could sell them in a week,” said Jack Smith, an independent gun dealer in Des Moines, referring to the popular style of semiautomatic rifle that drew national attention after Adam Lanza used one to kill 20 children and 6 adults at a Newtown school. “When I close, they beat on the glass to be let in,” Mr. Smith said of his customers. “They’ll wave money at me.”

Mr. Smith said many people were stocking up on high-capacity magazines in anticipation that they might be banned. Two weeks ago, he said, a 30-round rifle magazine was $12, but it now fetches $60. Popular online retailers were out of many 20- and 30-round rifle magazines.

In Washington, Mr. Biden said the task force he leads is “shooting for Tuesday” to make its recommendations to President Obama about preventing gun violence. The Brady Campaign to Prevent Gun Violence, one of the nation’s leading gun control groups, said its top priority was to close the loopholes that currently allow 40 percent of gun sales to be made without background checks.

Some groups that support gun control urged the White House not to focus too much energy on an assault weapons ban, which they said could be hard to persuade Congress to pass. Officials at Third Way, a left-leaning research group in Washington, urged the president to save his political capital for higher-priority goals like universal background checks and cracking down on gun trafficking.

Outside Greta’s Guns, a gun store in Simi Valley, Calif., about an hour northwest of downtown Los Angeles, several customers said that they opposed any assault weapons ban, but would support more thorough background checks.

George Gray, 60, who said that he already owned “more arms than arms to bear them,” said that he was in favor of more background checks. “If you own a weapon, you should be stable,” said Mr. Gray, who said he had come from Los Angeles to buy a gun for his daughter. “You should be accountable for your actions. I don’t mind stricter background checks. What we’ve done with the mental health in this country — these people used to get care and were in facilities. And in most of these instances, it’s been people with mental problems.”

Some customers at Greta’s said that they wanted to buy guns before any new gun control measures made it more difficult. Bob Davis, 64, said that he wanted a new pistol. “They want to take guns out of citizens’ hands,” he said. “So as a consequence I ordered a gun. And they’re not going to be able to get me a gun for like six months, because of the backlog. They can’t make guns fast enough.”

The gun industry expected a surge in sales even before the Newtown shooting. Gun sales rose after President Obama was first elected in 2008, and many manufacturers expected an increase in gun sales in the event of his re-election. “We believe the continued economic uncertainty and the outcome of the 2012 presidential election is likely to continue to spur both firearms and ammunition sales,” the Freedom Group, which owns Bushmaster, the company that makes the rifle used in Newtown, wrote in a financial report on the quarter that ended Sept. 30.

The possibility that the federal assault weapons ban — which lasted from 1994 to 2004 — might be reinstated was enough to spur sales of semiautomatic rifles with military-style features.

Dale Raby, who manages one of two Gus’s Guns shops in Green Bay, Wis., said his inventory of guns and ammunition was almost cleaned out, and that most of the interest was in AR-15-style rifles.

“I had almost fistfights over the remaining inventory of that type gun,” he said.

Joel Alioto, 44, an Iraq war veteran who lives in the area, said he recently sold an AR-15 rifle at a gun show for $1,700, more than three times what he had paid for it. “I think the shooting in Connecticut was a terrible thing,” said Mr. Alioto, who is unemployed. “But before the shooting the gun was worth 500 bucks. I don’t think I did anything wrong. I wanted to get my teeth done, get a computer and pay for my first year of Bible college.”

Brad Williamson, one of the owners of Quint’s Sporting Goods in Saraland, Ala., said the waiting lists for some products are double what they normally are — especially for guns that are mentioned in the gun control debate. “Whenever there’s a blip on the news about a particular model, the next day people want to come in wanting whatever they named,” he said. “When Biden makes his recommendation next week, you’re going to see another surge.”

At Georgia Arms in Villa Rica, Ga., west of Atlanta, the ammunition business was brisk, with dozens of the yellow bins that usually held ammunition empty. The Rev. Laurence Hesser, a pastor at Memorial United Methodist Church near Knoxville, stopped by because he had been unable to buy ammunition on the shop’s Web site, which halted sales because inventory was so low.

He likened the current run on ammunition to the rush to buy Twinkies last year after its maker, Hostess Brands, announced it was closing. “It’s the same thing,” he said. “When you are threatened with the possibility that you are going to lose something, you get a bunch of it.”