HR 3999 : Ban Bump Stocks

Position: Support Status: Died in a previous Congress

H.R. 3999: To amend title 18, United States Code, to prohibit the manufacture, possession, or transfer of any part or combination of ... parts that is designed and functions to increase the rate of fire of a semiautomatic rifle but does not convert the semiautomatic rifle into a machinegun, and for other purposes.


Introduced on October 10, 2017 by Carlos Curbelo [R-FL26] 37 cosponsors (19 D, 18 R)

Semi-automatic weapons are legal in America. Automatic weapons are illegal. But what about a device that converts a semi-automatic weapon into an automatic-like firearm?

Such a device, called a bump stock, was used in the Las Vegas massacre last week. The Automatic Gun Fire Prevention Act, labelled S. 1916 and H.R. 3999, was introduced by Sen. Dianne Feinstein (D-CA) and Rep. Carlos Curbelo (R-FL26) within days and would ban bump stock devices.


Last week’s massacre at a country music concert in Las Vegas was the deadliest in U.S. history, killing at least 59 people.

The perpetrator used bump stocks, an add-on to a gun which “bumps” the trigger to drastically increase the number of rounds fired. With bump stocks, a gun can shoot as many as 800 rounds per minute, equivalent to about 13 shots per second. As audio from the event demonstrated, a semi-automatic with a bump stock is not readily distinguishable from a fully automatic firearm.

Automatic weapons have been banned in the U.S. since 1986, yet a device that effectively turned a legal weapon into an illegal one was permitted nonetheless. The devices are obscure enough that many gun-owning NRA-endorsed congressional Republicans didn’t know what they were.

What supporters say

Speaker Paul Ryan (R-WI1), an ardent conservative, has come out in favor of banning bump stocks while other supporters argue the bill fixes a loophole which allows the circumventing of an existing gun control law that’s been on the books for decades — an argument that could in theory appeal to conservatives who often argue “enforce the existing law” on such other issues as immigration.

“Automatic weapons have been illegal for more than 30 years, but there’s a loophole in the law that can be exploited to allow killers to fire at rates of between 400 and 800 rounds per minute,” Senate lead sponsor Feinstein said in a press release.

“The only reason to fire so many rounds so fast is to kill large numbers of people,” Feinstein continued. “No one should be able to easily and cheaply modify legal weapons into what are essentially machine guns.”

And while the National Rifle Association had initially said it was open to the regulation of bump stocks, it opposes this bill (more on that below)

What opponents say

Some conservatives are opposed to any form of gun control on principle, declaring the Second Amendment inviolable.

One Republican opponent of the bill in particular has surprised many: Sen. Pat Toomey (R-PA), among the only Senate Republicans who voted for expanded background checks and a few other gun control measures in the wake of the 2012 Newtown massacre.

“I am very skeptical about legislation that attempts to ban features and particular guns,” Toomey said in explaining his reasoning, implying that he’s more amenable to reforms like background checks which affect every gun owner rather than targeting a specific subset.

Opponents also note that not a single one of the 91 U.S. mass shootings since 1982 used a fully automatic weapon. Ceasefire Oregon notes the reason if because fully automatic weapons are highly regulated under the National Firearms Act of 1934.