In 1939, the Supreme Court handed down its first significant ruling on the scope of the Second Amendment. It’s still having an impact today, but should it?

On Monday, a federal appeals court upheld the National Firearms Act’s (NFA) restrictions on shot-barrel rifles. It did so primarily by citing 1939’s US v. Miller since that ruling upheld the same law’s restrictions on short-barrel shotguns.

“In sum, Miller’ has direct application in [this] case,’ and we therefore follow it,” Judge Joshua Kolar wrote in US v. Rush. “This alone is dispositive and brings Rush’s challenge to a halt.”

Since the Supreme Court handed down Miller, however, it has also handed out five other significant Second Amendment rulings. Most notably, it issued landmark rulings in DC v. Heller and New York State Rifle and Pistol Association v. Bruen–with the latter establishing an explicit Second Amendment test. Does Miller survive those rulings, and does it still offer any insight?

First, what exactly does Miller say?

Well, not a whole lot. It is a short, unanimous opinion from a case that’s shrouded in controversy–perhaps more now than ever before. Even still, it doesn’t attempt to settle the question of what exactly the Second Amendment means.

Instead, the High Court in Miller focuses on just whether the text of the amendment specifically covered the short-barrel shotgun at issue in the case.

“In the absence of any evidence tending to show that possession or use of a ‘shotgun having a barrel of less than eighteen inches in length’ at this time has some reasonable relationship to the preservation or efficiency of a well regulated militia, we cannot say that the Second Amendment guarantees the right to keep and bear such an instrument,” Justice James Clark McReynolds wrote for a unanimous Court. “Certainly it is not within judicial notice that this weapon is any part of the ordinary military equipment or that its use could contribute to the common defense.”

The High Court’s justification for this finding has been the primary legacy of Miller ever since.

“[T]he Militia comprised all males physically capable of acting in concert for the common defense,” McReynolds wrote. “‘A body of citizens enrolled for military discipline.’ And further, that ordinarily when called for service these men were expected to appear bearing arms supplied by themselves and of the kind in common use at the time.”

That reasoning has lived on because, as Judge Kolar noted in the Seventh Circuit opinion, it served as the starting for the Supreme Court’s holding in 2008’s Heller case. The Heller Court argued Miller’s holding was not dispositive of an individual right to keep and bear arms. Instead, it merely established that not all weapons are protected under the Second Amendment.

“Miller stands only for the proposition that the Second Amendment right, whatever its nature, extends only to certain types of weapons,” Justice Antonin Scalia wrote for the majority. “It is particularly wrongheaded to read Miller for more than what it said, because the case did not even purport to be a thorough examination of the Second Amendment.”

The Heller Court went on to articulate a Miller-based standard for what constitutes a Constitutionally-protected arm.

“We may as well consider at this point (for we will have to consider eventually) what types of weapons Miller permits,” Scalia wrote. “Read in isolation, Miller’s phrase ‘part of ordinary military equipment’ could mean that only those weapons useful in warfare are protected. 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,” Scalia continued. “‘In the colonial and revolutionary war era, [small-arms] weapons used by militiamen and weapons used in defense of person and home were one and the same.’ Indeed, that is precisely the way in which the Second Amendment’s operative clause furthers the purpose announced in its preface. 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. That accords with the historical understanding of the scope of the right.”

The High Court then doubled down on the historical aspect of the inquiry in 2022’s Bruen. Still, it noted, and notably did not overturn, the “common use” standard in Miller.

“After holding that the Second Amendment protected an individual right to armed self-defense, we also relied on the historical understanding of the Amendment to demark the limits on the exercise of that right,” Justice Clarance Thomas wrote for the majority. “We noted that, ‘[l]ike most rights, the right secured by the Second Amendment is not unlimited.’ ‘From Blackstone through the 19th-century cases, commentators and courts routinely explained that the right was not a right to keep and carry any weapon whatsoever in any manner whatsoever and for whatever purpose.’ For example, we found it ‘fairly supported by the historical tradition of prohibiting the carrying of ‘dangerous and unusual weapons’ that the Second Amendment protects the possession and use of weapons that are ‘in common use at the time.'”

Judge Kolar and his colleagues on the Seventh Circuit panel that decided Rush certainly think that means Miller is still in good standing and still relevant.

“We are left with the conclusion that Miller survives Bruen. We also recognize that ‘the constitutional issues at stake are weighty.'” he wrote. “Therefore, while we meet our duty to address arguments raised directly by the parties, we also deem it appropriate to decide this case on the simple fact that Miller controls.”

They found Miller alone was enough to doom Rush’s defense. After all, the charges are nearly identical.

“Rush’s attempt to factually distinguish Miller is unavailing,” Judge Kolar wrote. “The fact that Miller involved an unregistered, short-barreled shotgun and Rush was convicted of possessing an unregistered, short-barreled rifle does not control the outcome of this appeal. Both are long guns with shortened barrels, which are dangerous because they are more powerful than traditional handguns yet are easier to conceal. And both involve a characteristic that makes the firearm especially attractive to criminals while adding little—if any—functionality to the firearm for lawful use.”

“Perhaps more importantly, both were regulated under the NFA provisions in effect at the time of the defendants’ convictions—provisions that simply required the registration of the firearms.”

Still, if anything, Kolar argued Heller and Bruen strengthened the case for the NFA’s short-barrel rifle regulations. The same goes for US v. Rahimi, the Supreme Court’s most recent Second Amendment ruling. In those cases, the High Court has not just established that firearms have to be in “common use” to be protected but also that permitting schemes and temporary gun restrictions present lesser burdens on the right to keep and bear arms.

“Rahimi and Bruen clarify the logic of Miller that onerous restrictions on weapons are distinct from licensing requirements of firearms,” Kolar wrote.

“§5861 is merely a taxing statute, so just as the ‘why’ regulates firearms with characteristics uniquely suitable for criminal purposes, the ‘how’ of the regulation has little impact on lawful possession for armed self-defense,” he continued. “Section 5861 does nothing to offend the Constitution that has stood as a bulwark between the people and governmental overreach for centuries. It simply makes those who desire a weapon likely to breach the peace register that weapon and pay a tax.”

There are a number of dubious contentions throughout this series of rulings that span nearly a century.

Miller‘s claim that short-barrel shotguns are neither common nor useful for militia service, especially coming off WWI where the trench gun was so effective the Germans claimed its use constituted a war crime, is unsupported by any evidence. Heller‘s claim that Miller wasn’t arguing military arms are most protected by the Second Amendment is puzzling. Rush‘s argument that the NFA targeted short-barrel shotguns and rifles because they’re particularly dangerous is highly disputed since that provision was originally part of a later-discarded handgun ban.

Still, the case law is relatively straightforward. Miller is not only still good law; it’s arguably the first building block of the Supreme Court’s entire Second Amendment jurisprudence. It survives Bruen because Bruen is based on Heller, which is itself based on Miller.

Of course, as Heller emphasizes, Miller doesn’t have a whole lot to say about the specifics of the Second Amendment. It just says that short-barrel shotguns aren’t popular enough to be protected. As the court in Rush determined, that’s probably enough to cover short-barrel rifles as well.

Now, it’s entirely possible the Supreme Court will eventually set a more solid standard for what constitutes “common use” that short-barrel rifles and shotguns end up falling into, especially if people keep buying more of them over time. Then Miller‘s practical holding will no longer apply, though its reasoning still will.

But that hasn’t happened yet. So, challenges to the NFA’s short-barrel regulations will likely continue to face an uphill battle.