The NRA, steadfastly against expanded gun regulation, now is ready to compromise on ‘bump stock’ devices. What happened?

The NRA does not budge in its opposition to stricter gun controls.

Not after 32 students and faculty were killed on the campus of Virginia Tech. Not after 12 people were murdered in a movie theater in Aurora, Colo. And not after 20 first-graders and six staffers were shot to death at Sandy Hook Elementary School in Newtown, Conn.

But now, days after a gunman killed at least 58 people at an outdoor country music festival on the Las Vegas Strip, the National Rifle Assn. has budged — at least a little.

NRA leaders issued a statement Thursday calling for regulation of “bump stocks,� a device that authorities said was used in the Las Vegas massacre to make semiautomatic firearms behave like a fully automatic ones.

The group said it “believes that devices designed to allow semi-automatic rifles to function like fully-automatic rifles should be subject to additional regulations,� while calling on the Bureau of Alcohol, Tobacco, Firearms and Explosives, which currently authorizes the sale of bump stocks, to implement tougher rules .

The statement also called on Congress to pass a law that would force states to honor concealed weapons permits issued in other states — suggesting to some gun control advocates that bump stocks were an easy place for the NRA to give up ground as it fights more significant battles over gun laws.

“This does not impact guns or manufacturers,� said Mark Rosenberg, a gun violence expert who has headed the Centers for Disease Control and Prevention’s National Center for Injury Prevention and Control. “These devices are accessories to firearms. Most mass murders don’t use these devices … most gun owners also don’t use them.�

The NRA’s position may also be an acknowledgment that it might be difficult to defend a court challenge to bump stocks. Federal law bans automatic weapons.

Still, Rosenberg said the statement is significant because it marks clear movement from the group. In 2002, NRA CEO Wayne LaPierre, laying out the group’s philosophical views on the Second Amendment, said “we must declare that there are no shades of gray in American freedom. It’s black and white, all or nothing.�

“These recent comments from the NRA are not black and white at all,� Rosenberg said. “They believe more regulation is needed. That’s promising.�

For Tom Sullivan, who became an avid gun control advocate after his son, Alex, was killed on his 27th birthday on July 20, 2012, in the Aurora movie theater, the NRA’s announcement came too late but was still welcome.

“Where has this been all along? Why not speak out against bump stocks before this happens,� he said. “It’s incremental, but it’s movement.�

For years, the NRA has spend hundreds of millions of dollars to defeat candidates — Democrats and Republicans alike — who support tougher gun laws. Last year, the NRA spent nearly $50 million in the presidential race and six competitive Senate contests, according to the nonpartisan Center for Responsive Politics, which tracks campaign spending. The group helped a majority of those candidates win their contests.

In 2012, following a string of high-profile mass shootings, President Obama and Democrats in Congress pushed for legislation to expand background checks. At no point did the NRA waver in its opposition and the effort failed as nearly all of Congressional Republicans opposed the effort.

This week, House Speaker Paul D. Ryan of Wisconsin and other Republicans expressed a willingness to regulate bump stocks.

Rep. Dina Titus, a Democrat from Nevada, whose district spans the The Strip, announced legislation this week to do just that. It would ban possession of bump stocks.

Titus said she is also exploring regulating other devices that can effectively turn a semi-automatic weapon into an automatic weapon, such as a glove that turns one pull of the trigger into multiple rapid shots.

“The NRA is suddenly realizing they’re going to have to do something,� Titus said, noting that some Republicans are supportive of her bill. “I think opposition to them — not in Congress, but in the community — is building and it has built over time.�

“Maybe it’s just the cumulative effect� of mass shootings, she said.

Times staff writer Seema Mehta contributed to this report.

[email protected]

Twitter: @kurtisalee