Some gun sellers say customers are rushing to buy bump stocks -- the accessories that make rifles fire like automatic weapons -- since the massacre in Las Vegas.

"Oh, God, yes, it's been insane. Since this story has broke, we've been getting about 50 people a day asking for them," said Michael Cargill, owner of Central Texas Gun Works in Austin, Texas. He said his distributors sold out, too.

Gun sellers told CNNMoney they believe the sales spike is driven by fears of tighter gun control -- perhaps including a ban on bump stocks -- since the attack in Las Vegas, the deadliest shooting in modern U.S. history.

Twelve bump stocks were found on firearms recovered at the Mandalay Bay hotel room of Stephen Paddock, the gunman, who killed 58 people in the assault Sunday night. In police body camera footage of the massacre, the sound of the gunfire resembles that of a fully automatic weapon.

Legislators of both parties have suggested bump stocks should be controlled more tightly or banned altogether. The National Rifle Association said Thursday that bump stocks should be subject to "additional regulations," and the White House signaled President Trump was open to discussing a ban.

There are no available nationwide figures on sales of bump stocks since the massacre. But sellers at stores in several states told CNNMoney that sales had taken off.

"Now that someone has come out saying maybe we should ban them, they're definitely going to sell off the shelf," Cargill said.

John Reid, owner of J.T. Reid's Gun Shop in Auburn, Maine, said "everybody's been wiped out" of bump stocks since the shooting. He said he had five on his shelf that were "sitting there collecting dust" for months and he sold four of them on Wednesday.

"All the distributors are out because customers bought them all," said Josh Dagnese, the owner of Village Gun Store in Whitefield, New Hampshire. "I am unable to reorder because of the demand." He said that he sold his last five bump stocks on Tuesday and hasn't been able to restock.

Slide Fire, a company that has sold bump stocks since 2013, announced on its website that it has stopped supplying the devices, as least for now.

"We have decided to temporarily suspend taking new orders in order to provide the best service with those already placed," said the company, based from Moline, Texas. Company officials did not return calls or emails from CNNMoney.

Another bump fire company, FosTech Outdoors of Seymour, Indiana, did not return messages, nor did Walmart (WMT) or Cabela's, which both sell guns. Online retailers Gunbroker.com and CheaperThanDirt were also not available. The gun industry group, the National Shooting Sports Foundation, declined to comment.

Related: Bump stocks mimic machine gun's rapid fire, and they're legal

Bump stocks are attached to semiautomatic rifles like AR-15s and AK-47s to speed up the rate of fire, leveraging the gun's own recoil to allow a person to fire faster than manual trigger-pulling. The accessories are legal. They retail for several hundred dollars.

Related: Vegas mass shooting had massive cache of weapons, ammo and explosives

Brice Jager, owner of Iowa Gun in Walnut, Iowa, said that although bump stocks do not require background checks, he conducts his own. He said he rejects customers who smell like alcohol or marijuana or "if they look a little unstable."

He said that he's rejected about a dozen would-be bump fire buyers since the shooting in Las Vegas, but he also sold two during his phone conversation with CNNMoney.

Some gun retailers frown on bump stocks because they make guns prone to jamming, inaccurate and difficult to control.

"I will order them if someone wants one, but I highly discourage them from purchasing," said Will Dance, a retailer with Red Hills Arms in Tallahassee, Florida. "It's not safe, they don't work, and it's a gimmick."

Julie Gipson, co-owner of Chestatee Firearms in Dahlonega, Georgia, says she sells full automatic guns for tens of thousands of dollars, but she doesn't sell bump stocks, which she described as "a pain in the butt to work with. If you really want to get a full automatic, pony up and get a real one."

--CNNMoney's Danielle Wiener-Bronner contributed to this report.