A majority of the justices on the nation’s highest court rebuked the ATF’s attempt to ban bump stocks by administrative rulemaking this week. However, several also expressed a curious openness to prohibiting the devices through other means.

On Friday, the Supreme Court handed down a decision against the ban in Cargill v. Garland. A 6-3 majority found the ATF had exceeded its authority under the National Firearms Act by reclassifying bump stocks as machineguns. The Court focused on the fact that bump stocks don’t fire more than one round per “function of the trigger,” as required to qualify as a machinegun under the law.

The majority opinion did not declare the Second Amendment protects bump stocks, which isn’t surprising since the challenge didn’t claim that. What is surprising is how many of The Court’s conservatives went out of their way to suggest the Second Amendment doesn’t protect bump stocks.

While all of the conservative members of the Court joined the majority in striking down the ATF ban, half of them expressed sympathy for its goal at one point or another. The first two instances came during oral arguments in the case. Justices Amy Coney Barrett and Neil Gorsuch implied they think the stocks, which help a shooter bump fire to reach a higher rate of fire than traditional shooting methods, shouldn’t be available to civilians.

During her questioning of the government, Barrett said she “can certainly understand why these items should be made illegal.” Her only real hangup with the ban was the way the ATF read it into existence.

“Look, intuitively, I am entirely sympathetic to your argument,” she said. “I mean, it — and it seems like, yes, that this is functioning like a machinegun would. But, you know, looking at that definition, I think the question is, why didn’t Congress pass that litigation — I mean that legislation to — to make this cover it more clearly?”

“Maybe they should have written something better. One might hope they might write something better in the future,” Gorsuch added. “But that’s the language we’re stuck with.”

Then, Justice Samuel Alito doubled down on his colleagues’ questions in a concurrence to Friday’s ruling.

“There can be little doubt that the Congress that enacted 26 U. S. C. §5845(b) would not have seen any material difference between a machinegun and a semiautomatic rifle equipped with a bump stock,” he wrote. “There is a simple remedy for the disparate treatment of bump stocks and machineguns. Congress can amend the law—and perhaps would have done so already if ATF had stuck with its earlier interpretation.”

“Now that the situation is clear, Congress can act,” Alito concluded.

More surprising, and perhaps alarming to gun-rights activists, is the lack of an explanation for how such a ban comports with the history and tradition standard set by the same majority just two years ago in New York State Rifle and Pistol Association v. Bruen. The three conservative justices simply assert bump stocks can be banned just by Congress instead of the ATF. They don’t wrestle at all with the idea the Second Amendment protects them.

Under Bruen, the government is meant to justify modern firearms restrictions using historical analogues that date to the Founding Era. The National Firearms Act, the underlying law the justices suggest amending to include bump stocks, only dates to 1934. Alito, Barrett, and Gorsuch haven’t offered up any historical analogues to justify it.

That’s a bad sign for anyone hoping the Supreme Court would use the Bruen standard to strike down most modern gun prohibition based on the relatively sparse Founding Era regulations.

It isn’t wholly unexpected to anyone who has watched The Court’s gun jurisprudence since it began finally developing one less than 20 years ago. Bruen may be the most recent and expansive standard developed by The Court to handle Second Amendment cases, but it isn’t the only one. US v. Heller set a different, though not necessarily contradictory, standard for what weapons are protected based on whether they are in common use by American civilians.

“Read in isolation, Miller’s phrase ‘part of ordinary military equipment’ could mean that only those weapons useful in warfare are protected,” the Heller majority wrote in reference to a previous Second Amendment ruling. “That would be a startling reading of the opinion, since it would mean that the National Firearms Act’s restrictions on machineguns (not challenged in Miller) might be unconstitutional, machineguns being useful in warfare in 1939. We think that Miller’s ‘ordinary military equipment’ language must be read in tandem with what comes after: ‘[O]rdinarily when called for [militia] service [able-bodied] men were expected to appear bearing arms supplied by themselves and of the kind in common use at the time.’ The traditional militia was formed from a pool of men bringing arms ‘in common use at the time’ for lawful purposes like self-defense.”

So, The Court believes the Second Amendment historically protected guns that were owned by the general population because they were the ones expected to turn up for militia service. That means any firearm that isn’t part of that to-this-point-vaguely-defined category is fair game for government regulation.

“We therefore read Miller to say only that the Second Amendment does not protect those weapons not typically possessed by law-abiding citizens for lawful purposes, such as short-barreled shotguns,” the majority wrote. “That accords with the historical understanding of the scope of the right.”

The ATF estimated there were about half a million bump stocks in circulation before the ban. That’s far fewer than handguns, which The Court found were protected under the common use standard. But it’s more than the stun guns that the Court found were protected. The Supreme Court has never given a hard number on what qualifies as “common use.”

Although, ironically, Alito’s concurrence in the stun gun case came the closest when he asserted that the estimate of 200,000 tasers put them in the protected category.

“The more relevant statistic is that ‘[h]undreds of thousands of Tasers and stun guns have been sold to private citizens,’ who it appears may lawfully possess them in 45 States,” he said. “While less popular than handguns, stun guns are widely owned and accepted as a legitimate means of self-defense across the country. Massachusetts’ categorical ban of such weapons therefore violates the Second Amendment.”

The flip side of “common use” is the “dangerous and unusual” standard. If a weapon hits both qualifiers, the government can ban it under Heller. The Justices seem to view bump stocks as especially dangerous. But Alito’s concurrences have muddied the water on the second point.

Regardless, his concurrence, combined with his conservative colleagues’ comments in oral arguments and the liberals’ dissent arguing bump stocks should already be banned under current law, suggest a new bump stock ban law would probably survive a Second Amendment challenge. It also indicates most of the conservative justices view Bruen as a less severe burden on the government’s ability to restrict firearms than many in the gun-rights legal movement do. Look for that basic truth to come through in The Court’s upcoming ruling in US v. Rahimi, too.