Wayne LaPierre, executive vice president of the National Rifle Association (NRA), said the NRA would be open to regulating devices that allow rifles to fire at a high rate similar to an automatic weapon. (Jim Lo Scalzo/European Pressphoto Agency/REX/SHUTTERSTOCK)

The National Rifle Association ventured into unfamiliar territory last week when it endorsed new restrictions on a device that accelerated gunfire in the Las Vegas massacre. But leaders of the gun lobby signaled Sunday they may draw a line at writing those restrictions into law.

“If we could legislate morality, we would have done it long ago,” Wayne LaPierre, the NRA’s executive vice president and chief executive, said in an interview on CBS’s “Face the Nation.”

Instead, LaPierre said the Bureau of Alcohol, Tobacco, Firearms and Explosives should review the matter. “I think you want to tell ATF to do its job. It’s an interpretive issue, and they need to get the job done,” he said.

The device, known as a bump stock, remained obscure until the Las Vegas shooting, for which Stephen Paddock fitted them on at least a dozen of the 23 firearms in his hotel room. The accessories helped him fire semiautomatic weapons with a rapidity approaching that of a fully automatic gun. His assault from the 32nd floor window of the Mandalay Bay Resort and Casino left 58 dead and hundreds injured in a matter of minutes.

Some rare bipartisan interest in a new gun restriction has emerged in the wake of Paddock’s attack, with lawmakers from both parties endorsing tighter controls on bump stocks. And the NRA lent weight to the effort last Thursday, releasing a statement from LaPierre and Chris W. Cox, executive director of the group’s Institute for Legislative Action, calling for “additional regulations” on accessories that allow semiautomatic rifles to mimic fully automatic ones.

Senators and congressmen from both parties as well as NRA officials on Oct. 8 addressed whether to restrict “bump stocks,” which allow semiautomatic weapons to fire more rapidly. (Bastien Inzaurralde/The Washington Post)

But despite Democrats’ apparent willingness to restrict the legislation to the bump stock ban, the NRA and some in Congress think the issue can be addressed without legislation if ATF reversed rulings made during the Obama administration that confirmed the devices were legal.

On Sunday, Cox stopped short of calling for a complete prohibition.

“We don’t believe that bans have ever worked on anything,” he said on “Fox News Sunday.” “What we’ve said has been very clear, that if something transfers a semiautomatic to function like a fully automatic, then it ought to be regulated differently. Fully automatics are regulated differently in this country.”

Sen. Dianne Feinstein ­(D-Calif.) said no Republicans have signed on as co-sponsors to a bill she is proposing that would ban the sale, transfer and manufacture of bump stocks, trigger cranks and other accessories that can accelerate a semiautomatic rifle’s rate of fire.

“Regulations aren’t going to do it. We need a law,” Feinstein, the top Democrat on the Senate Judiciary Committee, said on “Face the Nation.” “It can’t be changed by another president. Right now we’re seeing one president change actions of a president that came before him. And that would happen in this area. And I would hope that Americans will step up and say ‘Enough is enough. Congress, do something.’”

LaPierre suggested that Feinstein, who wrote the 1993 assault weapons ban, was seeking to use the issue as cover for a broader rollback of gun rights and “turn this all into some Christmas tree on the Hill where she brings all her anti-gun circus she’s been trying to for years into this.”

Feinstein rejected that characterization as “just plan wrong. This is written in clean English. You can take a look at it. It’s a two-page bill. It does not take anyone’s gun.”

She said her proposal has attracted Republican interest. Appearing on CNN’s “State of the Union” on Sunday, Sen. Ron Johnson (R-Wis.) said he also supported a ban on the accessories, whether it was through legislation or regulations. “However that gets fixed, I support,” he said. And in the House last week, Rep. Carlos Curbelo (R-Fla.) announced that he will be introducing a bill aimed at bump stocks and said he had been “flooded” with requests from other Republicans who want to back it.

That could put some Republican lawmakers at odds with the NRA.

Sen. Chris Murphy — a Democrat from Connecticut who emerged after the 2012 massacre at Sandy Hook Elementary School as a leading advocate of tighter gun laws — said Sunday that he would support a “clean bill” focused exclusively on banning the devices.

Speaking on “State of the Union,” he said that Congress needed to act in the wake of the Las Vegas massacre, and that the ban of the bump stock devices was an important first step. “You have to walk before you run,” he said.