(CNN) -- A federal ban on bump stocks -- attachments that essentially allow shooters to fire semiautomatic rifles continuously with one pull of the trigger -- will start Tuesday.
The Justice Department issued the rule in December, deciding that existing prohibitions against fully automatic weapons also covered bump stocks.
Owners were given 90 days to turn in or destroy them, and that period ends Tuesday.
Bump stocks came under scrutiny after the October 2017 massacre in Las Vegas. Stephen Paddock opened fire from his hotel suite onto outdoor concertgoers with rifles fitted with bump stocks, killing 58 people and wounding hundreds of others.
The Supreme Court on Monday night received at least two emergency appeals asking the justices to put the bump stock ban on hold.
In one case out of the District of Columbia called Guedes v. Bureau of Alcohol, Tobacco, Firearms and Explosives, two individuals who own bump stocks and three groups say the DC Court of Appeals has yet to rule on their appeal. They are asking the justices to put any ruling on hold for 48 hours after it comes down so the groups can file a timely appeal with the Supreme Court.
In another case out of the 6th Circuit, Gun Owners of America and other individuals are asking for a stay because they say the regulation issued by the Trump administration will become effective at midnight Monday. They say the administration's rule mandates the destruction of more than 500,000 bump stocks that are valued at over $100 million.
They argue the final rule "reverses well over a decade of consistent ATF classification of bump stocks as unregulated firearm accessories."