Shopping malls weren't the only places receiving an influx of shoppers on Black Friday: According to the FBI, the day after Thanksgiving saw record gun sales, with 154,873 checks conducted, a 20 percent increase from last year. And all those calls caused two brief outages for the bureau's National Instant Check System (NICS), the background check required for most gun sales in the U.S.

"The NICS never actually went down," said FBI spokesman Stephen Fischer. "The call centers experienced two short outages - one of 14 minutes and one of 18 minutes. These outages were caused by exceptionally large call volume."

NICS has access to information from computers at the FBI's Criminal Justice Information Services Division, searching records that would prohibit a buyer from owning a gun, such as being a fugitive, having a felony conviction or charge, renouncing U.S. citizenship, or having been determined as mentally impaired. NICS was mandated by the Brady Handgun Violence Prevention Act and set up in November 1998.

According to FBI officials, when West Coast gun dealers opened for business on Black Friday, the system was briefly impacted and FBI officials decided to take call centers offline so that systems could catch up with calls already in the queue.

Over the three days from Nov. 23 to Nov. 25, there were a total of 283,423 NICS checks, compared with 215,192 last year.

"We had several delays that didn't clear till the following morning," said Chuck Nesby, chief firearms instructor at NOVA Firearms, a retail gun dealer, in Falls Church, Va. In a brief interview with ABC News, Nesby said he had only three customers who had to wait. "It went relatively smooth actually."

Nesby said that sales at his store had been busy all week, noting that, following the presidential election, gun owners are concerned about new regulations. Nesby also cited a 15 percent increase in sales among women seeking guns for personal protection.

During the Oct. 16, 2012, presidential debate, Obama said he was open to reintroducing the assault weapons ban.

"Weapons that were designed for soldiers in war theaters don't belong on our streets," he said. "And so what I'm trying to do is to get a broader conversation about how do we reduce the violence generally. Part of it is seeing if we can get an assault weapons ban reintroduced."

"People are worried about gun control restrictions," Nesby said.

According to the FBI, since 1998 there have been more than 155 million NICS checks. Each check doesn't represent a single gun, just a single background check transaction.

"NICS has a 99.92% availability rate over the past 12 months, so system outages do not occur very often," Fischer said.