A federal judge in Texas recently declared that Congress lacked authority for decades of regulation under the National Firearms Act, a decision that spotlights how many firearm rules were drawn without clear evidence and leaves open major constitutional and policy questions about suppressors, short-barreled rifles, and modern semiautomatic rifles.

Silencers are quieter, but not silent. Courts and regulators have long treated suppressors as a special case, even though researchers tested nine AR-15s with fourteen suppressors and found the sound at the shooter’s ear often stayed above 140 decibels. OSHA puts the line for permanent hearing loss at 140 decibels of impulse noise, which means a suppressor reduces noise but does not make shooting harmless to hearing.

Last week a federal judge in Texas, James Wesley Hendrix, held that Congress never had the power to demand the fingerprint cards and federal paperwork tied to these items under a law dating to the National Firearms Act of 1934. The Justice Department chose not to seek a stay from the appeals court, so the ruling immediately affected the plaintiffs, their members, and their customers.

Medical and agency views have shifted. The American Academy of Otolaryngology endorsed suppressors “as an effective method of reducing the risk of hearing loss, especially when used in conjunction with conventional hearing protective measures.” An internal ATF white paper concluded “silencers are very rarely used in criminal shootings” and “should not be viewed as a threat to public safety necessitating NFA classification,” calling the historical rationale “archaic.”

Criminologists who reviewed federal silencer cases found that of roughly 40,000 homicides prosecuted in federal court, “considerably fewer than .01 percent involved a silencer.” Other democracies have already changed course; Britain moved to remove sound moderators from licensing for reasons including that they “are used to protect shooters’ hearing,” they “are entirely inert objects and contain no moving parts and do not of themselves create a risk to public safety,” and respondents “questioned whether there was any evidence to show that sound moderators had ever featured in crimes involving firearms.”

Many rules came from accident, not evidence. The 1934 law grew out of a bill aimed at pistols and revolvers, not rifles, and a bar-length line was inserted to avoid sweeping up ordinary hunting rifles. Representative Harold Knutson warned against anything that would “make it impossible for our people to keep arms that would permit them to hunt deer,” and Attorney General Homer Cummings said “there is no objection as far as we are concerned to including rifles after the word ‘shotguns’ if you desire.”

When pistols were later removed from the bill, the barrel-length rule stayed in place even though it no longer served the original purpose. The 1960 amendment shifted the threshold from eighteen inches to sixteen because “it is not believed that these guns constitute a type of weapon, such as a sawed-off rifle or shotgun, which is likely to be used by the criminal element.” Representative Bob Sikes recorded that such rifles “could not be considered concealable,” “they do not enter into the crime picture,” and “they still must be classed as a firearm subject to the taxation provisions of the law.”

Strategists picked targets that were easier to sell. In 1988 Josh Sugarmann argued that “Efforts to restrict assault weapons are more likely to succeed than those to restrict handguns.” He warned that defining “assault weapons” legally “is not easy,” and cautioned that it is not merely “a matter of going after guns that are ‘black and wicked looking.'”

Campaigns to restrict weapons often focused on outward features rather than measured risk. Christopher Koper told the Justice Department that the federal assault weapons ban “targets a relatively small number of weapons based on outward features or accessories that have little to do with the weapons’ operation. Removing some or all of these features is sufficient to make the weapons legal.” He added that “Relatively cosmetic changes,” “such as removing a flash hider or bayonet mount, are sufficient to transform a banned weapon into a legal substitute,” and concluded “we cannot clearly credit the ban with any of the nation’s recent drop in gun violence.”

Lawmakers and courts have struggled with definitions. States now ban rifles for a wide variety of cosmetic features, from thumbhole stocks to grips that can be held by the non-trigger hand, and places like Maryland list models by name while sweeping in copies carrying any two of an enumerated set of features. That patchwork is a direct result of creating categories without a consistent, evidence-based standard for what makes a rifle uniquely dangerous.

Judge Roger Benitez tested two AR-15s side by side and wrote, “The results were remarkably similar. Each rifle fired at approximately the same speed and accuracy. Any difference was hardly noticeable.” He concluded that “the prohibited features do not change an AR-15 rifle from a benign weapon into an ‘incredibly effective killing machine,'” and found the state “has not identified any relevant legislative history or legislative findings about the societal dangers of pistol grips, flash hiders, telescoping stocks, flare launchers or barrel shrouds.”

Real-world incidents expose the mismatch. Charlie Kirk was shot from a rooftop 160 yards away while speaking at Utah Valley University last September, and police found “a bolt-action .30-06 rifle,” wrapped in a towel. That bolt-action rifle is exempt under the assault weapons statutes of several states because those laws focus on semiautomatic action, not on the cartridge or range that did the harm.

Federal data show rifles of every type killed 364 people in the last year counted in this format, while clubs and hammers killed 397, knives 1,476, and handguns 6,368. Those numbers underline that policy choices have concentrated on certain platforms and features, not on the fuller picture of lethal violence.

Courts are finally confronting the question. Justice Clarence Thomas warned some lower courts “appear bent on distorting this Court’s Second Amendment precedents.” Several appeals courts upheld bans for years, but the Supreme Court has agreed to decide “Whether the Second and Fourteenth Amendments guarantee the right to possess AR-15 platform and similar semiautomatic rifles,” a question that will force a nationwide legal reckoning over definitions that were often set by accident rather than by data.