Cabela’s, the outdoor retailer, also took bump stocks off its website this week. The company, recently purchased by rival Bass Pro Shops, did not immediately respond to requests for comment.
Amazon does not sell bump stocks. The company explicitly forbids listings of “Slide fire stock and weapons kits, such as: bump firing devices, stocks, and kits,” according to its website. The policy has been in place “for a while — it’s not a recent change,” said a spokeswoman, Cecilia Fan.
But manufacturers of the devices said they were overrun with orders.
The website for one manufacturer, Bump Fire Systems, was down on Thursday. The company wrote on its Facebook page that its servers had been overwhelmed by “high traffic volume.”
Another maker, Slide Fire, said on its website that it had suspended taking new orders to focus on existing orders after earlier saying that it was out of stock “due to extreme high demands.”
Neither manufacturer responded to requests for comment.
Bump Fire sells stocks for an AK-47 and an AR-15 for $99.99 each. Slide Fire’s stocks are priced between $140 and $300.
On Slide Fire and Bump Fire’s Facebook pages, several customers suggested that the increased demand for bump stocks was due to fear that the products could soon be outlawed.
Senator Dianne Feinstein of California, along with more than two dozen other Democrats, proposed a bill on Wednesday to ban the accessory. The products allow semiautomatic weapons to be modified to perform at the level of automatic weapons, which are highly regulated, effectively creating a legal loophole, she said.
Top congressional Republicans also signaled that they would be open to banning bump stocks.
“The only reason to fire so many rounds so fast is to kill large numbers of people,” Ms. Feinstein said in a statement. “No one should be able to easily and cheaply modify legal weapons into what are essentially machine guns.”