CBS11's Jeff Paul contributed to this report

WASHINGTON and NORTH TEXAS (CBS11/AP) — The National Rifle Association announced its support Thursday for regulating “bump stocks,” devices that can effectively convert semi-automatic rifles into fully automated weapons and that were apparently used in the Las Vegas massacre to lethal effect.

It was a surprising shift for the leading gun industry group, which in recent years has resolutely opposed any gun regulations. Immediately afterward the White House, too, said it was open to such a change.

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The NRA announcement followed comments from leading congressional Republicans including House Speaker Paul Ryan that Congress should take a look at the devices, which were little-known even to gun enthusiasts prior to Sunday’s bloodbath. A gunman pumped bullets from a casino high-rise into a crowd of concertgoers below, killing 59 and wounding hundreds, apparently using legal “bump stocks” to increase firing speed from his semi-automatic weapons.

“I’m not happy right now, this is all still sinking in,” said David Prince, who owns Eagle Gun Range in Lewisville and Farmers Branch.

Prince had not heard about the announcement until reporters started calling his shop.

“I’ve never seen them fold this fast,” said Prince.

“The National Rifle Association is calling on the Bureau of Alcohol, Tobacco, Firearms and Explosives (BATFE) to immediately review whether these devices comply with federal law,” the NRA said in a statement. “The NRA believes that devices designed to allow semi-automatic rifles to function like fully-automatic rifles should be subject to additional regulations.”

Prince and other gun owners do not understand the move by the NRA.

“Call you members and ask them first before you make a statement like this,” said Prince.

While gun owners like Prince feel it’s a “knee-jerk reaction,’ gun control advocates like Hadi Jawad of The Dallas Peace and Justice Center were pleasantly shocked.

“I hope they mean what they’re saying and they’re serious about doing this,” said Jawad.

Jawad called it a good first step and is not suspicious of the NRA’s intentions at the moment.

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“This is not something to play around with. Too many lives have been lost,” said Jawad.

Prince is disappointed and has no plans to stop selling bump stocks for however long they remain legal.

“You’re not going to see a decrease in the number of mass shootings, mass killings,” said Prince. “It’s not going to stop evil people from doing evil things.”

The NRA and the Texas State Rifle Association did not immediately returns emails and calls for comment.

SALT LAKE CITY, UT – OCTOBER 5: A bump stock device, (left) that fits on a semi-automatic rifle to increase the firing speed, making it similar to a fully automatic rifle, is shown next to a AK-47 semi-automatic rifle, (right) at a gun store on October 5, 2017 in Salt Lake City, Utah. Congress is talking about banning this device after it was reported to of been used in the Las Vegas shootings on October 1, 2017. (Photo by George Frey/Getty Images)

White House spokeswoman Sarah Huckabee Sanders said in response, “We welcome that and a conversation on that. … It’s something we’re very open to. It’s something we want to be part of the conversation on going forward.”

President Donald Trump had discussed the issue with lawmakers on the way back from visiting Las Vegas on Wednesday, according to Rep. Mark Amodei, R-Nevada, who traveled with the president aboard Air Force One.

“Bump stocks” originally were intended to help people with limited hand mobility fire a semi-automatic without the individual trigger pulls required. They can fit over the rear shoulder-stock assembly on a semi-automatic rifle and with applied pressure cause the weapon to fire continuously, increasing the rate from between 45 and 60 rounds per minute to between 400 and 800 rounds per minute, according to the office of Sen. Dianne Feinstein, D-Calif., who introduced legislation this week to ban them.

The government gave its seal of approval to selling the devices in 2010 after concluding that they did not violate federal law.

The endorsement from the NRA and congressional Republicans for a change in law or policy to regulate guns, however narrow, marked a shift. Inaction has been the norm following other mass shootings, including the Sandy Hook, Connecticut, massacre of schoolchildren five years ago, last year’s bloodbath at the Pulse nightclub in Florida, and a baseball field shooting this year in which House Majority Whip Steve Scalise came close to death.

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(© Copyright 2017 CBS Broadcasting Inc. All Rights Reserved. The Associated Press contributed to this report.)