Seven survivors of the Jan. 8 mass shooting are lending their stories to the gun-control cause in a new video released Wednesday.

A group called Mayors Against Illegal Guns produced the video, which supports a bill, the Fix Gun Checks Act, that would increase the reach of the background checks required for some gun sales now.

"I'm going to work for this cause to hopefully keep other people from having to go through the horror we went through," survivor Mavy Stoddard says in the three-minute video's only mention of the gun-checks issue.

The rest of the video, taped in November in Washington D.C., recounts survivors' stories of Jan. 8.

Coincidentally, the video came out just one day after the FBI released 2011 figures from the National Instant Criminal Background Check System, or NICS, which showed an apparent spike in gun sales last year. The number of background checks on people who wanted to buy guns increased by 14 percent in 2011, or about 2 million checks over 2010, to 16.5 million.

In Arizona, the number of checks increased by 22 percent from 2010, hitting 251,477 in 2011.

The number of background checks doesn't have a one-to-one relationship with gun sales, because different states use the system differently, and in some cases buyers purchase more than one gun at a time or are rejected as buyers. But two Tucson gun-shop owners said their sales jumped in 2011.

"Generally it (a background check) does represent a sale," said Tom Rompel, owner of Black Weapons Armory, 5023 E. Fifth St. "It's rare that it doesn't."

Rompel said his store, which specializes in AR-15s and similar weapons, experienced a "significant" increase in sales in 2011. So did Doug MacKinley, owner of Diamondback Police Supply, 170 S. Kolb Road.

"We expect it to go up this year as we move toward the presidential election," MacKinley added.

Hearing in D.C.

The Jan. 8 survivors who appear in the video all attended a Nov. 15 congressional hearing in Washington, D.C., on the Fix Gun Checks Act.

That bill would require background checks for virtually all gun sales, even those between private individuals, not just those by licensed firearms dealers as currently mandated. It would also cut federal funding to states that do not adequately comply with reporting requirements.

At present, some states don't systematically provide the names of people prohibited from buying guns, such as people committed judicially to mental facilities, those convicted of domestic violence or proven abusers of illegal drugs.

But the video doesn't touch on any of the details of the proposal, focusing instead on the experiences of survivors such as Randy Gardner.

"Pop! Pop! Pop-pop-pop, and things went gray for me," he says in the video. "I could just see shadows. People were spreading out in front of me like a wave, trying to go for cover, falling to the ground."

As a quiet piano plays, survivor Roger Salzgeber goes on: "It's like death just passed right over you. I mean he was just shooting everybody right down the line."

Stoddard said Thursday she lent her voice to the cause even knowing that the law would not solve the gun-violence problem.

"We know that people can get illegal guns anywhere, but you have to take a first step," she said. "If we can stop the dealers from selling to the wrong people, at least that's one step."

Said Salzgeber on Thursday: "I'm a gun owner - in fact I own two. But I went through the process of obtaining these guns through background checks, in accordance with the law. The law right now leaves a gaping hole as far as someone being able to buy a gun without a background check."

"Reduce firepower"

Not everyone who supports gun restrictions thinks the gun-check system is the top priority.

Kristen Rand, legislative director at the Violence Policy Center, said a common thread in American mass shootings is that the perpetrators use semiautomatic pistols with high-capacity magazines, as Jared Loughner did on Jan. 8.

"Our opinion is that the most effective way to reduce gun violence and to prevent the kinds of incidents that we saw in Tucson is look at the guns themselves and reduce the level of firepower in the hands of civilians," Rand said.

That's the kind of change that gun-rights advocates and the firearms industry are worried about. Three such people interviewed Thursday said they cautiously support improving reporting to the NICS system but worry about federal firearms restrictions.

"We support the incorporation of prohibited persons, under current federal law, into NICS," Ted Novin, a spokesman for the National Shooting Sports Foundation, a firearms-industry group, said via email. "We do not support proposals that would curtail the lawful commerce of firearms or the Second Amendment rights of law-abiding Americans."