After a federal appeals court wrote AR-15s and the magazines that typically come with them out of the Second Amendment, a federal judge has written them back in.

Last November, a Seventh Circuit Court of Appeals panel declined to enjoin Illinois’ ban on so-called assault weapons and large capacity magazines after ruling that each was too akin to military hardware to be counted as “arms” protected by the Second Amendment. Yet just last week, a US District Court judge under the Seventh Circuit’s jurisdiction struck down the exact same ban as unconstitutional.

In fact, he did so by relying on the circuit’s own words.

When the Seventh Circuit panel upheld Illinois’ ban, it set a new standard to determine whether a proposed gun law implicates the plain text of the Second Amendment–a key component of the Supreme Court’s Bruen test.

“In order to show a likelihood of success on the merits, the plaintiffs in each of the cases before us thus have the burden of showing that the weapons addressed in the pertinent legislation are Arms that ordinary people would keep at home for purposes of self-defense, not weapons that are exclusively or predominantly useful in military service, or weapons that are not possessed for lawful purposes,” Judge Diane Wood wrote in Bevis v. Naperville.

Wood drew specific attention to the “military use” prong. Relying on dicta from the Supreme Court’s Heller decision assuring other courts that the ruling did not prohibit regulation of machineguns used by the military (specifically the M16), she posited that civilian AR-15s are nearly indistinguishable from M16s. She concluded, therefore, that they are also “predominantly useful in military service” and may be banned.

Judge Stephen McGlynn came to a different conclusion regarding the “military use” of AR-15s and similar rifles when reviewing the case. While following the analytical structure handed down by the Seventh Circuit, he conducted his own inquiry into what makes a weapon “predominantly useful in military service.” Where the Seventh Circuit panel hand-waved away rate-of-fire differences between AR-15s and military service rifles, McGlynn found cause for highlighting the distinction.

“The commercially available AR-15’s external similarity to the M16 rifle and M4 carbine belies its nature, as its lack of burst or fully automatic fire fundamentally renders it a different weapon,” he wrote.

He also argued that rifles acquired for the military are subject to unique standards of “military specificity and rigorous quality-insurance inspections,” whereas civilian-market AR-15s have no such standards. Ultimately, he concluded, these differences render the AR-15 outside the scope of the Seventh Circuit’s military use standard.

“The Court holds that ‘military use’ refers to weapons that are selected, procured, tested, and issued to military members for use in combat,” McGlynn wrote. “With this in mind, none of the weapons, magazines, or attachments prohibited by PICA can be called ‘military-grade’ since they were not issued to the military for use in combat.”

Furthermore, he noted that the Seventh Circuit previously recognized a “dual use” standard for categories of weapons that have both lawful civilian and military applications in Bevis and its pre-Bruen assault weapons ban rulings.

“Obviously, many weapons are ‘dual use’: private parties have a constitutionally protected right to ‘keep and bear’ them and the military provides them to its forces,” Judge Wood wrote. “In this sense, there is a thumb on the scale in favor of Second Amendment protection. When we refer to ‘military’ weapons here, we mean weapons that may be essentially reserved to the military.”

Though Judge Wood specifically had shotguns and semi-automatic handguns in mind, Judge McGlynn found that AR-15s and similar rifles could just as easily fit the bill.

“Even if arguendo there are no material differences between the M16/M4 and AR-15, so-called ‘dual use’ has clearly been established here,” he wrote. “Clearly, even though handguns are useful and are used in military service, they are clearly protected by the Second Amendment. However, as noted above, AR-15s are distinct from their military counterparts.”

Ultimately, Judge McGlynn’s analysis represents a response to an argument that has become increasingly common among federal appeals courts looking for rationales to uphold state assault weapon bans despite Bruen’s demanding standards. It could serve as a blueprint for gun-rights advocates as they continue challenging similar bans in courts that are primed to rule against their position.

At the same time, it may not be an argument that is necessary for very long. The Supreme Court has an opportunity to take up an assault weapon ban case very soon, one that many gun-rights advocates believe is their best opportunity yet to have the justices weigh in. Should they do so, Justice Clarence Thomas, a member of the likely majority in any hardware ban case, has already tipped his cap regarding his views on the Seventh Circuit’s “military use” analysis.

In a statement accompanying the High Court’s denial of cert after the Seventh Circuit upheld Illinois’ ban, Thomas accused the panel of “contorting” the justices’ past Second Amendment guidance to reach a “nonsensical” conclusion that the Second Amendment does not protect “militaristic” weapons like the AR-15.

“The Seventh Circuit’s contrived ‘non-militaristic’ limitation on the Arms protected by the Second Amendment seems unmoored from both text and history,” he wrote. “It is difficult to see how the Seventh Circuit could have concluded that the most widely owned semiautomatic rifles are not ‘Arms’ protected by the Second Amendment.”

It may not matter much to gun-rights advocates in the end whether they’ve found an analytical avenue through the Seventh Circuit’s novel reading of the Bruen test for hardware bans. However, the Court has not been eager to take up an “assault weapons” ban case to this point. So, these lower court battles may continue to take on an outsized importance.