In this Feb. 1, 2013, file photo, an employee of North Raleigh Guns demonstrates how a “bump” stock works at the Raleigh, N.C., shop. The gunman who unleashed hundreds of rounds of gunfire on a crowd of concertgoers in Las Vegas on Monday, Oct. 2, 2017, attached what is called a “bump-stock” to two of his weapons, in effect converting semiautomatic firearms into fully automatic ones.
ATLANTA — The Las Vegas gunman possessed a little-known device called a “bump stock” that was not widely sold — until now.
Originally created with the idea of making it easier for people with disabilities to shoot a gun, the attachments allow a semi-automatic rifle to mimic a fully automatic weapon by unleashing an entire large magazine in seconds. Now the deadliest mass shooting in modern U.S. history has drawn attention to the devices, which critics say flout federal restrictions on automatic guns.
The stocks have been around for less than a decade. The government gave its seal of approval to selling them in 2010 after concluding that they did not violate federal law.
The device basically replaces the gun’s shoulder rest with a “support step” that covers the trigger opening. By holding the pistol grip with one hand and pushing forward on the barrel with the other, the shooter’s finger comes in contact with the trigger. The recoil then causes the gun to buck back and forth, repeatedly “bumping” the trigger against the finger.
Technically, that means the finger is pulling the trigger for each round fired, keeping the weapon a legal semi-automatic. The rapid fire does not necessarily make the weapon any more lethal — much of that would be dependent on the type of ammunition used. But it does allow the person firing the weapon to get off more shots more quickly.
It’s unclear how many have been sold. The industry leader, Slide Force, did not return messages seeking comment. But the Abilene, Texas, company’s Facebook page is filled with videos extolling its features, including one in which a woman gushed, “It’s so easy because once you slid it forward and leaned into it, it just fires.” In another video, a man fires off 58 rounds to celebrate his 58th birthday in just 12 seconds.
Sales for firearms or specific accessories seem to jump after every high-profile shooting. That will likely happen again with bump stocks, said Dr. Garen Wintemute, director of the Violence Prevention Research Program at the University of California, Davis.
“People will go, ‘Oh geez, I should get one of those.’ The other is that people will be concerned about efforts to ban them,” Wintemute said.
Manufacturers tout the stocks, some of which sell for less than $200, as offering a simple and affordable alternative to automatic weapons without the hassle of a rigorous background check and other restrictions.
Ed Turner, a former police officer who owns a gun shop in Stockbridge, Georgia, said he’s already seeing a run on bump stocks since the shooting. He said he would be surprised if he had sold two of them in the past decade, but now he’s unable to find any available, even from wholesalers.
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People run for cover at the Route 91 Harvest country music festival after apparent gun fire was heard on Oct. 1, 2017 in Las Vegas, Nevada. There are reports of an active shooter around the Mandalay Bay Resort and Casino.
David Becker, Getty Images
People run from the Route 91 Harvest country music festival after apparent gun fire was heard on Oct. 1, 2017 in Las Vegas, Nevada. There are reports of an active shooter around the Mandalay Bay Resort and Casino.
Las Vegas police stand guard along the streets outside the festival grounds of the Route 91 Harvest on Oct. 1, 2017 in Las Vegas, Nevada. There are reports of an active shooter around the Mandalay Bay Resort and Casino.
John Locher, The Associated Press
Police officers advise people to take cover near the scene of a shooting near the Mandalay Bay resort and casino on the Las Vegas Strip, Sunday, Oct. 1, 2017, in Las Vegas.
David Becker, Getty Images
People take cover at the Route 91 Harvest country music festival after apparent gun fire was heard on Oct. 1, 2017 in Las Vegas, Nevada. There are reports of an active shooter around the Mandalay Bay Resort and Casino.
David Becker, Getty Images
A man lays on top of a woman as others flee the Route 91 Harvest country music festival grounds after a active shooter was reported on Oct. 1, 2017 in Las Vegas, Nevada. The photographer witnessed the man help the woman up and they walked away. Injuries are unknown.
David Becker, Getty Images
A person lies on the ground covered with blood at the Route 91 Harvest country music festival after apparent gun fire was heard on Oct. 1, 2017 in Las Vegas, Nevada.
Chase Stevens, Las Vegas Review-Journal via AP
People run from the New York New York during an active shooter situation on the Las Vegas Stirp in Las Vegas Sunday, Oct. 1, 2017. Multiple victims were being transported to hospitals after a shooting late Sunday at a music festival on the Las Vegas Strip.
John Locher, The Associated Press
Police run to cover at the scene of a shooting near the Mandalay Bay resort and casino on the Las Vegas Strip, Sunday, Oct. 1, 2017, in Las Vegas. Multiple victims were being transported to hospitals after a shooting late Sunday at a music festival on the Las Vegas Strip.
David Becker, Getty Images
People run from the Route 91 Harvest country music festival after apparent gun fire was heard on Oct. 1, 2017 in Las Vegas, Nevada. There are reports of an active shooter around the Mandalay Bay Resort and Casino.
David Becker, Getty Images
People run from the Route 91 Harvest country music festival after apparent gun fire was heard on Oct. 1, 2017 in Las Vegas, Nevada. There are reports of an active shooter around the Mandalay Bay Resort and Casino.
John Locher, The Associated Press
A police officer takes cover behind a truck at the scene of a shooting near the Mandalay Bay resort and casino on the Las Vegas Strip, Sunday, Oct. 1, 2017, in Las Vegas. Multiple victims were being transported to hospitals after a shooting late Sunday at a music festival on the Las Vegas Strip.
John Locher, The Associated Press
A police officer takes cover behind a police vehicle during a shooting near the Mandalay Bay resort and casino on the Las Vegas Strip, Sunday, Oct. 1, 2017, in Las Vegas.
John Locher, The Associated Press
Police stand at the scene of a shooting along the Las Vegas Strip, Monday, Oct. 2, 2017, in Las Vegas. Multiple victims were being transported to hospitals after a shooting late Sunday at a music festival on the Las Vegas Strip.
Chase Stevens, Las Vegas Review-Journal via AP
A wounded person is walked in on a wheelbarrow as Las Vegas police respond during an active shooter situation on the Las Vegas Stirp in Las Vegas Sunday, Oct. 1, 2017. Multiple victims were being transported to hospitals after a shooting late Sunday at a music festival on the Las Vegas Strip.
John Locher, The Associated Press
Police officers and medical personnel stand at the scene of a shooting near the Mandalay Bay resort and casino on the Las Vegas Strip, Monday, Oct. 2, 2017, in Las Vegas. Multiple victims were being transported to hospitals after a shooting late Sunday at a music festival on the Las Vegas Strip.
John Locher, The Associated Press
A woman sits on a curb at the scene of a shooting outside of a music festival along the Las Vegas Strip, Monday, Oct. 2, 2017, in Las Vegas. Multiple victims were being transported to hospitals after a shooting late Sunday at a music festival on the Las Vegas Strip.
Chase Stevens, Las Vegas Review-Journal via AP
A man waits during lockdown at the Tropicana Las Vegas during an active shooter situation on the Las Vegas Strip Sunday, Oct. 1, 2017. Multiple victims were being transported to hospitals after a shooting late Sunday at a music festival on the Las Vegas Strip.
Chase Stevens, Las Vegas Review-Journal via AP
People assist a wounded woman at the Tropicana during an active shooter situation on the Las Vegas Stirp in Las Vegas Sunday, Oct. 1, 2017. Multiple victims were being transported to hospitals after a shooting late Sunday at a music festival on the Las Vegas Strip.
Chase Stevens, Las Vegas Review-Journal via AP
Las Vegas police sweep through a convention center area during a lockdown Monday, Oct. 2, 2017, at the Tropicana Las Vegas following an active shooter situation on the Las Vegas Strip. Multiple victims were transported to hospitals after a deadly shooting late Sunday at a music festival on the Las Vegas Strip.
Chase Stevens, Las Vegas Review-Journal via AP
People are searched by Las Vegas police at the Tropicana Las Vegas during an active shooter situation on the Las Vegas Strip on Sunday, Oct. 1, 2017. Multiple victims were being transported to hospitals after a shooting late Sunday at a music festival on the Las Vegas Strip.
Steve Marcus, Las Vegas Sun via AP
A body is covered with a sheet after a mass shooting in which dozens were killed at a music festival on the Las Vegas Strip on Sunday, Oct. 1, 2017.
Ethan Miller, Getty Images
People hug and cry outside the Thomas and Mack Center after a mass shooting at the Route 91 Harvest country music festival on Oct. 2, 2017 in Las Vegas, Nevada. A gunman, identified as Stephen Paddock, 64, of Mesquite, Nevada, opened fire from the Mandalay Bay Resort and Casino on the music festival, leaving at least 50 people dead and hundreds injured. Police have confirmed that one suspect has been shot. The investigation is ongoing.
Chip Somodevilla, Getty Images
The U.S. flag flies at half-staff over the White House Oct. 2, 2017 in Washington, DC. President Donald Trump ordered the flags on all federal buildings to fly at half-staff following the mass shooting that left more than 50 dead in Las Vegas. The gunman, identified as Stephen Paddock, 64, of Mesquite, Nevada, opened fire from the Mandalay Bay Resort and Casino on an outdoor music festival. Police have confirmed that one suspect has been shot. The investigation is ongoing.
Alex Wong, Getty Images
U.S. President Donald Trump makes a statement on the Las Vegas mass shooting at the Diplomatic Room of the White House October 2, 2017 in Washington, DC. The gunman, identified as Stephen Paddock, 64, of Mesquite, Nevada, opened fire from the Mandalay Bay Resort and Casino on the music festival, leaving at least 50 people dead and hundreds injured. Police have confirmed that one suspect is dead. The investigation is ongoing.
Evan Vucci, The Associated Press
President Donald Trump makes a statement about the mass shooting in Las Vegas, Monday, Oct. 2, 2017 at the White House in Washington.
Mark Wilson, Getty Images
A Park Service employee lowers the U.S. flags on the grounds of the Washington Monument to half-staff, on Oct. 2, 2017 in Washington, DC. President Donald Trump ordered the flags on all federal buildings to fly at half-staff following the mass shooting that left more than 50 dead in Las Vegas. The gunman, identified as Stephen Paddock, 64, of Mesquite, Nevada, allegedly opened fire from the Mandalay Bay Resort and Casino on an outdoor music festival. Police have confirmed that one suspect has been shot. The investigation is ongoing.
John Locher, The Associated Press
MGM Resorts announced Friday that it does not plan to rent out room No. 32135 at Mandalay Bay Resort and Casino, the perch from which Stephen Paddock shot and killed 58 people and injured more than 500.
Ronda Churchill, The Associated Press
People walk near the Las Vegas Strip shortly after sunrise Monday, Oct. 2, 2017, in Las Vegas. A deadly shooting occurred Sunday at a music festival on the Las Vegas Strip.
Ronda Churchill, The Associated Press
A woman speaks on the phone while walking along the Las Vegas Strip near Mandalay Bay hotel and casino Monday, Oct. 2, 2017, in Las Vegas. A mass shooting occurred late night Sunday at a music festival on the Las Vegas Strip. (AP Photo/Ronda Churchill)
Ethan Miller, Getty Images
Concert-goers wait for a ride outside the Thomas & Mack Center after a mass shooting at a country music festival on Oct. 2, 2017 in Las Vegas, Nevada. People who could not go to hotel-casinos that were closed after the shooting temporarily stayed at the center. The gunman, identified as Stephen Paddock, 64, of Mesquite, Nevada, opened fire from the Mandalay Bay Resort and Casino on the music festival, leaving at least 50 people dead and hundreds injured. Police have confirmed that one suspect has been shot. The investigation is ongoing.
Al Powers, Invision/AP
Women make phone calls while taking shelter inside the Sands Corporation plane hangar after a mass shooting in which dozens were killed at Route 91 Harvest Festival on Sunday, Oct. 1, 2017, in Las Vegas.
Ethan Miller, Getty Images
United Blood Services phlebotomist Sha-Na Hill (L) takes blood from Richard Williams of Nevada at a special United Blood Services drive at a University Medical Center facility to help victims of a mass shooting on Oct. 2, 2017 in Las Vegas, Nevada. A lone gunman opened fired on the Route 91 Harvest country music festival on October 1 leaving more than 50 dead and hundreds wounded.
Mark Ralston, AFP/Getty Images
Crime scene tape surrounds the Mandalay Hotel after a gunman killed at least 50 people and wounded more than 200 others when he opened fire on a country music concert in Las Vegas, Nevada on Oct. 2, 2017.
Police said the gunman, a 64-year-old local resident named as Stephen Paddock, had been killed after a SWAT team responded to reports of multiple gunfire from the 32nd floor of the Mandalay Bay, a hotel-casino next to the concert venue.
David Becker, Getty Images
Las Vegas police investigate a side street near the Las Vegas Village after a lone gunman opened fired on the Route 91 Harvest country music festival on Oct. 2, 2017 in Las Vegas, Nevada. The gunman, identified as Stephen Paddock, 64, of Mesquite, Nevada, allegedly opened fire from a room on the 32nd floor of the Mandalay Bay Resort and Casino on the music festival, leaving at least 58 people dead and over 500 injured. According to reports, Paddock killed himself at the scene.
David Becker, Getty Images
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People run for cover at the Route 91 Harvest country music festival after apparent gun fire was heard on Oct. 1, 2017 in Las Vegas, Nevada. There are reports of an active shooter around the Mandalay Bay Resort and Casino.
Jay Wallace, owner of Adventure Outdoors in Smyrna, Georgia, said soon after most of his customers buy one, “the newness wears off and they put it away and it stays in a closet.”
While the stocks allow a gun to quickly spray bullets, gun experts say they also create such a jolt that accuracy is affected. That may not matter to gun owners who just want the thrill of shooting with one, or for those bent on destruction. Stephen Paddock, the 64-year-old gunman, fired hundreds of rounds indiscriminately from his 32nd-floor room at the Mandalay Bay Hotel and Casino on a music festival outside.
He had 23 guns in the room. Authorities found bump stocks attached to 12 of the weapons, Bureau of Alcohol, Tobacco and Firearms Special Agent in Charge Jill Schneider said.
At Paddock’s home, authorities found 19 more guns, explosives and thousands of rounds of ammunition. Several pounds of ammonium nitrate, a fertilizer that can be turned into explosives, were in his car, authorities said.
The shooting renewed a push by some lawmakers to ban bump stocks. California Sen. Diane Feinstein, a Democrat, said the devices can enable a gun to fire 400 to 800 rounds per minute and “inflict absolute carnage.”
The purchase of fully automatic weapons has been significantly restricted in the U.S. since the 1930s. The National Firearms Act was amended in 1986 to prohibit the transfer or possession of machine guns by civilians, with an exception for those previously manufactured and registered.
Numerous attempts to design retrofits failed until bump stocks came on the market.
Erich Pratt, executive director of Gun Owners of America, said the industry is prepared to have the devices scrutinized by lawmakers and gun-control advocates. That happens regularly after a major shooting. But he and others defended their use, suggesting it’s unfair to go after firearms when other weapons — trucks and fertilizer, for example — aren’t as quickly criticized after deadly attacks.
“Ultimately, when Congress … looks at this, they’ll start asking questions about why anybody needs this, and I think the answer is we have a Bill of Rights and not a Bill of Needs,” Pratt said.
Kevin Michalowski, executive editor of Concealed Carry Magazine, agreed.
“If he used fully automatic weapons, he likely got them illegally. If he used aftermarket parts, he used them for illegal activities,” Michalowski said. “For whatever reason, this man wanted to kill lots of people. … Adding extra restrictions to guns, magazines or accessories will not prevent others from committing mass murder.”
Associated Press writers Sadie Gurman in Washington and Michael Balsamo in Las Vegas contributed to this report.