100% of Americans Support No sales to “known or suspected terrorists” Expand mental health treatment Stronger sentences for illegal guns Report lost or stolen guns Universal checks for gun buyers Bar sales to all violent criminals Bar sales to convicted stalkers Centralized record of gun sales Require safety training 3-day waiting period Bar sales to mentally ill Require gun safes Universal checks for ammo buyers Require gun licenses Fingerprint gun owners Ban on Bump Stocks Govt. buyback of banned guns Assault weapons ban Honor out-of-state conceal and carry permits Gun purchase limit Guns that microstamp bullets Ammo purchase limit School weapons ban Semiautomatic gun ban EXperts say not effective High-capacity magazine ban Experts Say Effective Workplace weapons ban Demonstrate a need for a gun 0% of Americans Support 3.5 4.0 4.5 5.0 5.5 100% of Americans Support No sales to “known or suspected terrorists” Expand mental health treatment Report lost or stolen guns Universal checks for gun buyers Stronger sentences for illegal guns Bar sales to all violent criminals Centralized record of gun sales 3-day waiting period Bar sales to mentally ill Require gun safes Require gun licenses Fingerprint gun owners Universal checks for ammo buyers Govt. buyback of banned guns Ban on Bump Stocks Assault weapons ban Honor out-of-state conceal and carry permits Guns that microstamp bullets Ammo purchase limit Gun purchase limit School weapons ban Semiautomatic gun ban High-capacity magazine ban EXperts say not effective Experts Say Effective Workplace weapons ban Demonstrate a need for a gun 0% of Americans Support 3.5 4.0 4.5 5.0 5.5 100% of Americans Support No sales to “known or suspected terrorists” Universal background checks Expand mental health treatment Bar sales to violent criminals Bar sales to mentally ill Require gun licenses Ban on Bump Stocks Assault weapons ban School weapons ban EXperts say not effective Experts Say Effective Ammo purchase limit Workplace weapons ban Demonstrate a need for a gun 0% of Americans Support 3.5 4.0 4.5 5.0 5.5

A ban on the “bump stock” devices that made the Las Vegas attack so deadly would enjoy broad public support, according to a new poll. Yet gun policy experts say a ban would probably have a negligible effect on mass shooting deaths.

In the aftermath of the attack, in which 58 people were killed at a country music festival on Oct. 1, the only gun-related legislation generating any serious political discussion is a ban on bump stocks, devices that enable a semiautomatic weapon to shoot nearly as fast as a machine gun.

A bump stock ban was supported by 72 percent of registered voters in a survey conducted last week for The Upshot by Morning Consult, a polling and media company. The measure even garnered 68 percent support from Republicans; Democrats favored it by 79 percent.

Stephen Paddock, the Las Vegas shooter, had affixed bump stocks to a dozen weapons found in the hotel room where he conducted the shooting, and the pattern of his fire was consistent with their use. His is the first high-profile mass shooting to involve such a device.

But several gun policy experts said it was difficult to assess the safety benefits of making such devices harder to obtain.

“Until now, bump stocks have been a non-issue in firearm homicide (mass or not),” wrote April Zeoli, an associate professor at the Michigan State University School of Criminal Justice, in an email. “But now that the door has been opened for their use, I suspect that future mass shooters may use them.”

Ms. Zeoli was one of a panel of experts we surveyed about an array of gun control ideas last year. On average, the experts we were able to recontact thought that banning bump stocks was likely to have a small effect on mass shooting fatalities. They ranked it similarly to requiring gun owners to complete safety training and requiring technology that stamps each bullet with a mark that can trace it to a particular gun.

Our poll last year showed that the public favors many gun control ideas, including some that our experts thought would be more effective than a bump stock ban: Universal background checks and restrictions on guns sales to people with violent misdemeanor convictions were substantially more popular. Last week Politico and Morning Consult conducted a poll on those very same measures, and public opinion about them hasn’t shifted much since last year.

The future of a bump stock ban is uncertain. Legislation from Senator Dianne Feinstein, a Democrat from California, has received a warm if not enthusiastic reception from several Republicans in Congress. President Trump said the White House would look into the idea, despite promises to use his presidency to expand gun rights. The National Rifle Association, which is generally opposed to any gun restrictions, did not entirely reject the idea, though it indicated that it hoped for regulatory restrictions and not a legislative ban. But the legislation has not progressed and might not.