The Supreme Court is so far declining to stop the Trump administration from enforcing its ban on bump stock devices, which allow semi-automatic weapons to fire like machine guns.
The ban took effect Tuesday. The administration is in the unusual position of arguing against gun rights groups. Gun rights groups asked the court Monday to keep the government from beginning to enforce the ban for now. Chief Justice John Roberts declined a request for the court to get involved Tuesday. A second request is pending in front of Justice Sonia Sotomayor.
President Donald Trump said last year that the government would move to ban bump stocks. The action followed a 2017 Las Vegas shooting where bump stocks were used. Fifty-eight people were killed.
It's the only major gun restriction imposed by the federal government in the past few years, a period that has seen massacres in places like Las Vegas; Thousand Oaks, California; Sutherland Springs and Santa Fe, Texas; and Orlando and Parkland, Florida.
Unlike with the decade-long assault weapons ban, the government isn't allowing existing owners to keep their bump stocks. They must be destroyed or turned over to authorities. And the government isn't offering any compensation for the devices, which can cost hundreds of dollars. Violators can face up to 10 years in prison and thousands of dollars in fines.
The U.S. Bureau of Alcohol, Tobacco, Firearms and Explosives first ruled that bump stocks were legal in 2010, and since then, the government estimates more than 500,000 have been sold.
They were originally created to make it easier for people with disabilities to fire a gun. The device essentially replaces the gun's stock and pistol grip and causes the weapon to buck back and forth, repeatedly "bumping" the trigger against the shooter's finger.
Technically, that means the finger is pulling the trigger with each round fired, a distinction that led the ATF to allow the devices.
They were considered by most gun owners to be a novelty and weren't widely known until a gunman attached bump stocks to several of the AR-type rifles he used to rain bullets on concertgoers outside his high-rise Las Vegas hotel room.
The attachments were swiftly condemned by even ardent gun supporters, including President Donald Trump, who directed the Justice Department to rewrite the regulations to ban them. The impending ban was announced in mid-December.
Owners are being advised to either destroy them by crushing, melting or cutting them up or set up an appointment with the ATF to hand the devices over.
A week before the ban was set to take effect, bump stocks were being sold on websites and by at least one company that took over the inventory of Slide Fire, the Texas manufacturer that was the leading maker and has since shut down.