Updated at 6:30 p.m. with House passage of concealed carry bill and comments from lawmakers.

WASHINGTON — A survivor of the Las Vegas massacre tearfully pleaded with senators Wednesday to ban bump stocks, the device the killer added to his rifles so he could gun down scores of concertgoers in minutes. And the head of the Bureau of Alcohol, Tobacco, Firearms and Explosives said the agency will review its decision to allow the unregulated sale of the devices.

Lawmakers are grappling with conflicting approaches to gun violence. Two of the deadliest mass shootings in modern U.S. history took place 35 days apart this fall, claiming more than 80 lives.

The House voted Wednesday afternoon to let gun owners use a concealed carry permit from their home state anywhere in the country.

That came shortly after a Senate Judiciary Committee hearing at which acting ATF director Thomas Brandon announced that the agency will re-evaluate its hands-off approach to bump stocks. The attachments allow a shooter to fire a rifle at nearly automatic rates.

Brandon told senators that if regulation or a ban "wasn't a possibility at the end, we wouldn't initiate this process."

The agency has received pressure from GOP lawmakers, who argue that Congress should not have to pass legislation to ban the device. The Justice Department announced Tuesday that it will re-examine the decision with ATF.

But Democrats saw the review as an effort to deflate congressional efforts aimed at a permanent ban.

Sen. Dianne Feinstein, the top Democrat on the Senate Judiciary Committee, authored a bill to ban bump stocks. The legislation, which has bipartisan support, has not moved forward.

"While some have argued that the ATF can ban or regulate these devices under existing law, the ATF has repeatedly stated that bump stocks cannot be regulated because they do not fall within the legal definition of a machine gun," Feinstein said in her opening remarks at Wednesday's hearing.

Heather Gooze recalled her night of bartending at the Vegas country music festival that turned into a night of pulling co-workers and concertgoers to safety. Finally, she stopped outside the venue to help a man on a maintenance ladder being used as a makeshift stretcher.

“I kept holding this unnamed man’s hand and then his hand stopped holding mine,” she said. Gooze stayed with the man, later identified as Jordan McIldoon, until he was taken away by emergency personnel.

She urged lawmakers to ban bump stocks.

"Those devices are not for hunting. They are not for target practice. They are for hurting people," Gooze said. "And they have no place in our general society."

First hearing since shootings

Wednesday was the first Senate hearing since the mass shootings in Las Vegas and Sutherland Springs to address firearm accessories like bump stocks and the federal background check system.

Texas Sens. John Cornyn and Ted Cruz, both members of the Judiciary panel, kept a focus on flaws in the National Instant Criminal Background Check System, or NICS. Devin Kelley, who killed 26 people at a Sunday church service in Sutherland Springs, had a criminal history that made him ineligible to buy guns legally.

Both @SenTedCruz & @JohnCornyn making it clear that they believe Stephen Willeford kept more people from dying in #SutherlandSprings. https://t.co/GhVuSNugvz — Nicole Cobler (@nicolecobler) December 6, 2017

"It is simply unacceptable when you look across the United States Department of Defense, and the failure to upload this essential information, this required information, in the background check system," Cornyn said at the hearing. "And I hope if anything good comes out of this tragedy, it will be that we finally fix, on a bipartisan basis, this broken background check system."

Pushing back against Democrats and gun control advocates, Cornyn and Cruz pointed to the efforts of Stephen Willeford, the good Samaritan who shot the Sutherland Springs shooter as he exited the South Texas church, as reason for lawmakers to stay away from any attempts to restrict gun access. The two senators said his efforts kept more people from dying.

"The answer, I believe, is in not restricting law-abiding citizens," Cruz said. "The answer, instead, is stopping criminals and madmen from getting guns."

Air Force officials have admitted that Kelley's domestic violence conviction wasn't shared with the FBI, allowing him to buy guns without being flagged.

Air Force Secretary Heather Wilson testified Wednesday that such failures to report criminal history data are widespread. She assured senators that the Air Force is undertaking a complete review to ensure that around 60,000 records dating to 2002 have been properly reported.

It's not yet clear if any Air Force personnel will face disciplinary action.

"When all of the facts are compiled and there is a final report, commanders — with the advice of counsel — make decisions about any accountability or any disciplinary action," Wilson said.

David Slayton, administrative director for the Texas Office of Court Administration, told the Judiciary committee that the state's own reporting system has improved significantly in the last five years.

“We feel Texas has made great strides in improving the reporting of mental health and domestic violence disqualifiers,” Slayton said.

Broad support for background fix

Cornyn authored bipartisan legislation, known as the "Fix NICS Act," with Connecticut Sen. Chris Murphy, one of the most vocal Democrats on gun control. The bill would penalize federal agencies that fail to report criminal records, and it would give incentives to states to keep the federal database updated.

The proposal enjoys broad support, unlike the more controversial concealed carry bill approved by the House — a top priority for the National Rifle Association. The House bill includes language similar to the Fix NICS Act.

Rep. Henry Cuellar, a Laredo Democrat, applauded the House bill for ensuring the federal database is as accurate as possible. He authored the background check portion, and issued a joint statement with Republican Rep. John Culberson of Houston, who authored the concealed carry language.

"For the first time, Americans whose names were incorrectly added to the list have a guaranteed due process right to have their name removed within 60 days after they prove the error to the Attorney General," they said.

Tyler Rep. Louie Gohmert was the only Texas Republican to vote against the bill. He said that although he supports concealed carry reciprocity, he was concerned about expansion of the federal background check database. In a video message issued after the vote, he asserted that 92 percent of the 3 million people denied a gun purchase were wrongly denied. Many more Americans would lose their right to buy a gun because "some bureaucrat" put them on a list, he said.

"The NRA, God bless them, they're normally right," Gohmert said of the powerful gun rights group that supported the combined measure. "They're not always right, and I believe this is one of those times."

Cornyn, the No. 2 Senate Republican, supports reciprocity but warned that pairing those two measures could hamper efforts to improve the background check system.

"I support both of those bills but I recognize that if you combine them, that that makes it much harder to pass the consensus bill, which is the Fix NICS bill," he said. "But I respect the House's right to do what they want to do and what they need to do there for the votes."