Sen. Feinstein introducing bill to ban bump stocks after Vegas shooting The ATF said multiple bump stocks were found in the room used by the shooter.

 -- Sen. Dianne Feinstein, a longtime advocate of stricter gun control measures, introduced a bill Wednesday that would ban the sale and possession of bump-stock equipment and other devices that essentially turn a semiautomatic weapon into an automatic one.

The Bureau of Alcohol, Tobacco, Firearms and Explosives (ATF) told reporters Tuesday that multiple bump stocks were found in the hotel room used by the shooter, who opened fire during the Route 91 Harvest Music Festival on Sunday, killing 58 people and injuring over 500 others.

According to a copy of the bill text provided to ABC, it would go into effect 180 days after its passage.

“It shall be unlawful for any person to import, sell, manufacture, transfer or possess, in or affecting interstate or foreign commerce, a trigger crank, a bump-fire device or any part, combination of parts, component, device, attachment or accessory that is designed or functions to accelerate the rate of fire of a semiautomatic rifle but not convert the semiautomatic rifle into a machine gun,” the bill states.

The ban would not apply to sales or possession of the devices by U.S. agencies or departments.

Feinstein, who in 2013 authored an assault weapons ban bill, which failed 40-60 in the Senate, currently has 24 co-sponsors of the bill, all Democrats.

Republican leaders have pushed back on Democrats' calls for tightening gun control legislation after the shooting, calling the demands premature.

"I think it's particularly inappropriate to politicize an event like this," Senate Majority Leader Mitch McConnell, R-Ky., said Tuesday. "The investigation's not even been completed. And I think it's premature to be discussing legislative solutions if there are any."

"In the meantime, our priority is on tax reform, as my colleagues have indicated," McConnell added.

ABC News' Benjamin Siegel contributed to this report.