A federal judge has ruled that the Biden administration's sweeping ATF regulation on ghost guns violates the Second Amendment and is unconstitutionally vague, a decision that reopens a legal fight the government thought it had already won.
U.S. District Judge Reed O'Connor found that the Bureau of Alcohol, Tobacco, Firearms and Explosives overstepped when it imposed regulations treating homemade firearm kits the same as fully manufactured guns. The rule required ghost gun kits to carry serial numbers, forced sellers to obtain federal licenses, and mandated background checks on buyers. O'Connor, a George W. Bush appointee, concluded the regulation fails on two constitutional grounds: it infringes on the right to bear arms and is drafted so poorly that ordinary people cannot tell what conduct it prohibits.
The ruling lands in the middle of a broader legal reckoning over federal firearms regulation, one that has already produced landmark decisions on suppressors and semiautomatic weapons bans in federal courts across the country.
O'Connor applied Supreme Court precedent requiring courts to weigh American historical tradition when evaluating the constitutionality of gun laws. By that measure, he found the ATF's rule does not just lack historical support, it flatly contradicts it. The judge wrote in his opinion:
"The Final Rule does not merely lack supporting analogues. It contradicts the actual historical tradition of personal gunsmithing."
He went further, tracing the practice of building one's own firearms back to the founding era. Americans made their own weapons before the country existed, O'Connor noted, and that tradition persisted for centuries without government interference.
"Self-manufacture of firearms in America was common and indeed foundational to establishing our Nation. Americans throughout our history have continued to build their own arms and that 'right [has] remained unregulated throughout [much of] American history.'"
That historical record left the Biden-era rule without a constitutional leg to stand on. The ATF tried to regulate a practice that Americans have engaged in freely since before the Revolution, and the judge concluded the agency had no authority to do so under the Second Amendment.
The constitutional problems did not stop with the Second Amendment. O'Connor also struck down the regulation as unconstitutionally vague, meaning the rule was written so unclearly that a law-abiding citizen could not reasonably determine what was legal and what was not.
Adam Kraut, executive director of the Second Amendment Foundation, one of the two plaintiffs in the case alongside Defense Distributed, did not mince words about the quality of the regulation. Kraut said:
"This rule was such a mess that it not only violated the Second Amendment but was so terribly drafted that it managed to be ruled unconstitutionally vague."
That combination, a rule that both violates a fundamental right and is too incoherent to enforce, is a damning indictment of the Biden ATF's rulemaking. The agency did not just push the boundaries of its authority. It produced a regulation so muddled that even people trying to comply could not figure out how. A similar federal ruling earlier struck down the same ghost gun rule on both Second and Fifth Amendment grounds, underscoring the depth of the regulation's legal defects.
Kraut elaborated on the chilling effect the regulation created:
"The Court rightly held that the Biden ATF's rule not only sought to outright prohibit Second Amendment protected conduct but was written in such a vague and vaporous manner as to chill that protected conduct by making it impossible to even know what was legal and what wasn't."
O'Connor's ruling arrives more than a year after the Supreme Court weighed in on the same regulation. In March 2025, the justices ruled 7-2 that the ATF was acting within the scope of its rulemaking authority when it created the ghost gun rule. Justice Neil Gorsuch authored the majority opinion.
But the high court's decision was narrower than many observers assumed. The justices addressed only whether the ATF had the statutory power to issue such a rule. They did not rule on whether the regulation itself was constitutional, leaving that question for lower courts to resolve on remand.
O'Connor has now answered that open question with a resounding no. The ATF may have had the administrative authority to write the rule, but the rule it wrote cannot survive constitutional scrutiny. The distinction matters: having the power to regulate does not mean any regulation you produce is lawful.
The broader Second Amendment legal landscape continues to shift. Federal appeals courts have issued conflicting rulings on firearms restrictions, with the Third Circuit striking down New Jersey's semiautomatic rifle ban while the Seventh Circuit upheld Illinois's semiautomatic weapons ban in a split decision that may force the Supreme Court's hand.
One of the more unusual dimensions of this case is the Trump administration's position. The Department of Justice has continued to defend the Biden-era ghost gun rule in court, placing the administration on the opposite side of gun rights organizations in a legal fight. Earlier this year, DOJ filed a motion arguing that the court should dismiss the claims brought by Defense Distributed and the Second Amendment Foundation, largely on standing grounds.
O'Connor rejected that argument and reached the merits, delivering a ruling that hands gun rights advocates a significant victory, one achieved against a regulation their own political allies in the executive branch were defending.
The DOJ now faces a decision: appeal O'Connor's ruling to the U.S. Court of Appeals for the Fifth Circuit, or let it stand. If the government appeals, the case could eventually return to the Supreme Court for a full constitutional ruling, this time on the substance, not just the ATF's procedural authority.
The Trump administration's willingness to let certain gun-related rulings stand has varied. In a separate case involving suppressors, the Justice Department declined to challenge a landmark ruling that allowed suppressor transfers without federal registration for the first time in 92 years.
O'Connor's ruling is not the last word on federal firearms regulation. The Supreme Court has already agreed to hear a case on "assault weapons" bans in its next term, taking up challenges to restrictions in Connecticut and Cook County, Illinois. Arguments have not been scheduled but could occur as soon as December.
That case will test whether state and local bans on semiautomatic firearms can survive the same historical-tradition analysis O'Connor applied to the ghost gun rule. If the court applies the framework consistently, bans that lack deep roots in American legal history face an uphill fight.
For now, the ghost gun ruling stands as a pointed rebuke to an agency that tried to regulate a centuries-old American practice out of existence through administrative fiat. The Biden ATF wrote a rule that violated a constitutional right and could not even be understood by the people it governed.
When a regulation manages to fail on both counts, the problem is not the court that struck it down, it is the bureaucracy that wrote it.
