Gun Buyers Grab Up ‘Bump Fire Stocks’ Used In Las Vegas Massacre

Gun Buyers Bid Up ‘Bump Fire Stocks’ Used In Las Vegas Massacre

(Bloomberg) -- “Bump fire stocks,” devices that allow semi-automatic weapons to be fired as if they are fully automatic, were allegedly used by the gunman who killed almost 60 people at a Las Vegas concert Sunday. The question now being asked is why such items, which are being scooped up by gun buyers fearing new regulations, are so easily purchased when an automatic firearm is so hard to get?

More than 500 people were injured in the attack on the Route 91 Harvest festival when Stephen Craig Paddock allegedly opened fire from a 32nd floor room in the Mandalay Bay Resort. Among several weapons found at the scene were the devices that allowed him to fire more rapidly, killing and injuring more concertgoers than would be possible with a semi-automatic rifle alone.

The Bureau of Alcohol, Tobacco, Firearms, and Explosives is tasked with deciding whether bump fire stocks are legal under existing federal statute. The classification depends on whether “they mechanically alter the function of the firearm to fire fully automatic,” said Jill A. Snyder, ATF special agent in charge, during a press conference on Tuesday evening. “Bump fire stocks, while simulating automatic fire, do not actually alter the firearm to fire automatically, making them legal under current federal law.” 

U.S. Senator Dianne Feinstein of California, a Democrat, decried the use of bump fire stocks as a “loophole,” saying Tuesday that she would look into introducing legislation aimed at banning the devices. “The sale and manufacture of automatic weapons have been illegal since 1986. Automatic weapons produced before 1986 are highly regulated and tracked by the ATF,”  Feinstein said in a statement. “A ban on bump fire stocks was included in my 2013 assault weapons bill, and I’m looking at how best to proceed with legislation to finally close this loophole. This is the least we should do in the wake of the deadliest mass shooting in U.S. history. It should be our highest priority.”

Gun Buyers Grab Up ‘Bump Fire Stocks’ Used In Las Vegas Massacre

A semi-automatic weapon releases one round of ammunition per trigger pull. A bump fire stock expedites the process. “The user generates a forward activation force that urges the firing unit forwardly so that the trigger collides with the stabilized finger, stimulating the first round of ammunition in the receiver,” states the website of Slide Fire Solutions Inc., one maker of such devices. “A recoil force from the discharging ammunition pushes the firing unit rearwardly so that the trigger separates from the stabilized finger.” Other manufacturers include Bump Fire Systems LLC and Fostech Outdoors LLC.

In less technical terms, the bump fire stock effectively increases the rate of fire of a semi-automatic gun, said Kristen Rand, legislative director of the Violence Policy Center. “In the case of these bump fires, the ATF has made the determination that the shooter is repeatedly working the trigger. It just makes the gun fire faster but the trigger is being pulled for each round,” she said. A 2010 letter from the ATF notes that “the stock has no automatically functioning mechanical parts or springs and performs no automatic mechanical function when installed.”  (The ATF didn’t immediately respond to  a request for comment.) 

Any attempt to ban such bump stocks will likely be met with strident opposition from the gun lobby, led by the National Rifle Association. And even if a “loophole” in the automatic weapons ban were closed, the devices may fall under the Protection of Lawful Commerce in Arms Act, which prohibits gun dealers and manufacturers from being held liable for crimes committed with their weapons. A lawsuit filed by victims of the 2012 Sandy Hook school shooting, where elementary school children in Connecticut and their teachers were massacred inside their classrooms with a Remington Arms Co. assault weapon, was dismissed by a judge as a result of the act, which was passed in 2005. 

Gun Buyers Grab Up ‘Bump Fire Stocks’ Used In Las Vegas Massacre

“Whether bump-fire and other similar devices would be protected by the PLCAA would turn on whether it is considered to be a ‘qualified product,’” explained Rand. “The definition of ‘qualified product’ includes “a component part of a firearm or ammunition.” Rand wasn’t familiar with any prior litigation in which such language had been used.

Jonathan Lowy, vice president of litigation at the Brady Center to Prevent Gun Violence, said bump stocks might not be protected under the act because they are an accessory to a firearm, rather than a firearm. “There is a very strong argument that if you are selling a product that will foreseeably be used by people who want to essentially use a machine gun, or something like it, that’s unreasonable and negligent,” he added. In the event that bump stocks are protected under the PLCAA, a victim could attempt to argue that her case falls under the “negligent entrustment” exception, explained Ari Freilich, a staff attorney at the Brady Center. One scenario in which this exception is used is when a gun retailer sells a weapon to a visibly unwell person or an individual who threatens an attack while making the purchase.

Whether bump fire stocks are protected under the law will come down to whether they are defined as “a component part of a firearm” or not, as the act provides some immunity from civil litigation over firearms, ammunition, and component parts. Legal experts are unclear about whether the act will protect this particular type of accessory, and comparable cases are lacking, Freilich said. If a lawsuit is filed against such a manufacturer, a lengthy and complex legal debate would likely ensue, drawing the attention of both the gun control and Second Amendment lobbies.

The ATF didn’t reveal the manufacturer of the bump fire stocks police said they found in Paddock’s hotel room. Slide Fire, one of the companies that makes them, was overwhelmed with visitors to its website Wednesday, according to its Facebook page. “I can’t log on the website for some reason? I would like to purchase one,” wrote Robert Lopez Jr. “Probably overloading the website.” 

“Need to get me a few before outlawed with the sad news in Vegas,” wrote Facebook user Matt Mclynn. Concerns that the product might no longer be available may have led to a rise in prices for the devices. In a comment on Slide Fire’s Facebook page, another user noted that prices for the devices were increasing on, which bills itself as the “world’s largest online auction site for firearms and hunting/shooting accessories.” A used Slide Fire SSAR-15 bump stock had amassed eight bids and was selling for $315 on the auction site. The retail price on Slide Fire’s website for a similar device is $179.95, but it was sold out.

While it remains unclear whether bump stock makers have been sued over the use of their products, Slide Fire has been going to court of its own volition—to protect its intellectual property. In 2011, it sued Bumpmaster for copyright infringement related to the device. The case was later settled on undisclosed terms. In 2014, the company sued Bump Fire, alleging patent infringement. That case was settled last year, and the defendants agreed not to infringe on Slide Fire’s patents. Slide Fire also sued Bair Arms LLC in a case that was settled earlier this year on undisclosed terms. Bump Fire couldn’t immediately be reached for comment. Slide Fire and the other companies didn’t immediately respond to requests for comment. 

To contact the author of this story: Polly Mosendz in New York at

To contact the editor responsible for this story: David Rovella at