The National Rifle Association may have gotten its way when the Bureau of Alcohol, Tobacco, Firearms and Explosives announced it would revisit its decision not to regulate bump stocks. By putting the onus on the bureau, the NRA helped defuse bipartisan momentum for a Congressional ban on the rapid-fire devices, whose public safety risks were made clear by the  mass shooting in Las Vegas last October.

But some of the gun owners who make up the group’s base are not happy about the move. Thousands of gun-rights advocates have submitted public comments to the Federal Register slamming the ATF’s application to classify bump stocks as machine guns. If the bureau changes how it classifies bump stocks, the products could be subject to strict regulation under the National Firearms Act.

A number of the gun-rights commenters posted remarks first circulated by the hardline Virginia Citizens Defense League. Bump stocks can greatly accelerate the rate of fire of a semiautomatic rifle, but the VCDL focuses on a technical distinction: “A semi-automatic firearm equipped with a bump stock still fires only one round with each pull of the trigger.”

The remarks continue, “As long as one pull of the trigger fires one shot on a semi-automatic firearm, no accessory can be legitimately classified as a ‘machine gun.'”

Action by the ATF to regulate bump stocks would spare NRA allies in Congress from choosing between opposing a new restriction that enjoys overwhelming public approval, or passing a new restriction before securing any significant gun-rights victories.

However, this Beltway jiu-jitsu may have the NRA on the wrong side of the country’s most ideologically committed gun owners, whom the gun group typically tries to avoid alienating, said Robert Spitzer, a gun policy expert at the State University of New York at Cortland.

This appeal to the ATF is [the NRA’s] effort to thread the needle by not supporting congressional action, which is higher profile,” while still giving “a very small sop to the wishes of the public at large,” Spitzer wrote in an email. However, “the NRA is in a box of its own design. It has been whipping up its base against the imminent apocalypse for many years, making it nearly impossible to backtrack to support even limited measures like the bump stock ban.”

Prominent pro-gun outlets have bristled at the NRA-brokered compromise.

“Republican majorities are in the House and in the Senate, and a Republican president is in the White House. They wouldn’t be there were it not for gun owners,” David Codrea wrote on the blog Ammoland in late December. “We’re being asked to help provide cover to rationalize yet another Intolerable Act, and this one with the sanction of our ‘gun rights leaders.’”

On his website The Truth About Guns, Robert Farago was aghast that the NRA would suggest the ATF had the legitimacy to make rules at all.

We’ve seen what the Bureau’s done with their power in the past. The NRA’s implicit endorsement can only make them stronger,” Farago wrote. “All the Devil wants is your soul. Has the NRA delivered?”

The public comment period continues until January 25. So far, more than 2,300 comments have been submitted to the Federal Register.