Bump stocks “turn legal weapons into illegal machines,” President Trump.

As the federal government faced the prospect of a shutdown, last Tuesday, Dec. 18, the Trump administration quietly banned bump stocks. Bump stocks are firearm attachments designed to allow semi-automatic weapons to fire at the speed of fully automatic firearms.

In March President Donald Trump said the devices “turn legal weapons into illegal machines,” promising the ban on bump stocks at that time. White House Press Secretary Sarah Huckabee Sanders said that Trump was “once again fulfilling a promise he made to the American people.”

The Bureau of Alcohol, Tobacco, Firearms and Explosives (ATF) estimates that between 280,000 and 520,000 of the devices have been sold since 2010. Since bump stocks are untraceable, the exact number that Americans own is unknown.

A senior Justice Department official told the Associated Press that the majority of gun owners are expected to follow the new regulation, and ATF will “take action against” those who fail to comply.

Acting Attorney General Matthew Whitaker signed the regulation on Tuesday. He said in a press release: “President Donald Trump is a law and order president, who has signed into law millions of dollars in funding for law enforcement officers in our schools, and under his strong leadership, the Department of Justice has prosecuted more gun criminals than ever before as we target violent criminals. We are faithfully following President Trump’s leadership by making clear that bump stocks, which turn semiautomatics into machine guns, are illegal, and we will continue to take illegal guns off of our streets.”

In 2010 the ATF decided that bump stocks were not the equivalent of machine guns, and that they could only be regulated if Congress passed a new law or amended the existing one. After the Las Vegas shooting in 2017, some Congress members wanted to ban bump stocks, but no legislation was passed at the time. Since then, more than 10 states have tried to pass their own regulations.

Slide Fire Solutions, the largest manufacturer of bump stocks, said in April that it would shut down its website and no longer accept orders for the devices. RW Arms, a company in Forth Worth, Texas is selling the remaining stock.

The recent regulation reverses ATF’s 2010 decision and has been met with resistance from many gun rights advocates. Gun Owners of America’s executive director Erich Pratt said, “These regulations implicate Second Amendment rights, and courts should be highly suspect when an agency changes its ‘interpretation’ of a statute in order to impair the exercise of enumerated constitutional rights.”

The National Rifle Association asked for amnesty for those who already own bump stocks. Spokeswoman Jennifer Baker said, “We are disappointed that this final rule fails to address the thousands of law-abiding Americans who relied on prior ATF determinations when lawfully acquiring these devices.”

Specifically, the final rule amends the definition of machine gun by adding the following: “The term ‘machine gun’ includes bump-stock devices, i.e., devices that allow a semiautomatic firearm to shoot more than one shot with a single pull of the trigger by harnessing the recoil energy of the semi-automatic firearm to which it is affixed so that the trigger resets and continues firing without additional physical manipulation of the trigger by the shooter.”

The ruling gives owners of these devices until March 2019 to destroy or turn in their bump stocks.