When it comes to regulating fully automatic weapons in the United States, there is a puzzling paradox: even though the President called for a ban on these conversion devices, 80% of the public supported it, and even the National Rifle Association—which almost universally opposes gun control—rarely voiced support for regulation, the ban ultimately failed. Many instinctively assume this was the result of gun lobby pressure or indifferent politicians. In reality, there was no conspiracy at work; it was simply the expected outcome of a system of checks and balances functioning as designed.
When discussing American gun ownership, many assume that anyone can easily purchase submachine guns or machine guns. In reality, the opposite is true. Under federal law, genuine fully automatic weapons have been strictly regulated for decades.
In 1934, Congress passed the National Firearms Act, establishing a strict registry and special taxation for machine guns. By 1986, federal law completely slammed the door shut on new civilian machine guns: ordinary citizens could no longer purchase any fully automatic weapon manufactured after May 19 of that year.
Today, virtually every firearm available in licensed gun stores is semiautomatic. The defining feature of a semiautomatic firearm is that each trigger pull fires only a single round; the shooter must release the trigger, allowing it to reset to its original position, before another round can be discharged. It was only with the later emergence of various conversion devices that this barrier was breached.
One type is a coin-sized conversion switch attached to the back of a handgun. Installed in place of the slide cover plate, it alters the pistol’s mechanics. In a standard handgun, the internal mechanism disconnects the firing linkage after each shot, requiring the trigger to be released to reset. But this small component features a protruding metal tab that holds down the internal disconnector as the slide cycles, eliminating the semiautomatic restriction entirely. As long as the trigger remains held down, the pistol can achieve a cyclic rate of roughly 1,200 rounds per minute. On the black market, these switches can cost as little as $20; they can be produced on consumer 3D printers, and substantial numbers are smuggled in from abroad.
The other type is the bump stock, which leaves the firearm’s internal components completely untouched. It is a two-piece sliding shoulder stock with an internal spring, designed to replace a rifle’s standard fixed stock. During firing, the shooter holds their trigger finger stationary in midair while their other hand pushes the entire rifle forward. When a round fires, recoil drives the firearm backward, compressing the spring; forward tension and the spring’s rebound then propel the rifle forward again, slamming the trigger into the stationary finger. As long as the shooter maintains this posture, the rifle reciprocates using its own recoil, pushing the rate of fire to between 400 and 800 rounds per minute. Both conversion devices can unleash devastating bursts of fire in seconds, but they achieve it through entirely different mechanisms.
Once a semiautomatic weapon is modified to fire at full-auto rates, its lethality surges exponentially within seconds. That danger reached its zenith in the fall of 2017 in Las Vegas. From a high-rise hotel suite hundreds of yards away, a gunman perched behind bump-stock-equipped rifles unleashed 1,049 rounds into a crowded outdoor music festival. The attack killed 58 people and injured hundreds more, marking the deadliest mass shooting in modern American history. As investigative reporting on the Las Vegas shooting noted, the rapid rate of fire enabled by bump stocks exerted lethal suppressive fire over a dense crowd from a distance.
The destructive power of full-auto handguns is equally horrifying. In 2023, during a teenager’s birthday party in Dadeville, Alabama, a shooter opened fire on the crowd with a converted handgun, leaving behind 89 spent shell casings and resulting in 4 deaths and 32 injuries.
Because conversion devices are cheap and easy to obtain, they proliferated rapidly across the country. Over a five-year period, recoveries of these devices by federal law enforcement agencies responsible for firearm regulation surged by more than 570%, with cumulative seizures surpassing 30,000 units. At Chicago customs alone, more than 1,500 illicit devices shipped from overseas were intercepted in 2024.
The catastrophic casualties prompted an extraordinarily unified public response. Multiple nationwide surveys indicated that between 70% and 81% of Americans favored an outright ban on bump stocks. Even the National Rifle Association, a staunch opponent of gun control legislation, took the unprecedented step of issuing a statement acknowledging that devices designed to let semiautomatic rifles simulate fully automatic fire should be subject to additional regulations. The White House promptly directed officials to shut down the use of such conversion devices. (public statement)
In the face of such devastating casualties and overwhelming public support, many may wonder: if virtually everyone agreed, why couldn’t the federal government simply issue a decree to ban them?
Yet these are two fundamentally different questions. Whether something ought to be banned is one matter; whether it can legally be banned is another.
Whether it should be banned is a practical consideration grounded in real-world consequences. Confronted with mass tragedy, the answer seems straightforward: these devices grant civilians military-grade firepower, so of course they should be prohibited.
Whether it can be banned, however, hinges strictly on statutory authority. Under the American constitutional system, the exercise of executive power is subject to rigorous constraints: the executive branch cannot create new authority merely because something is dangerous. Every ounce of regulatory power it wields must be rooted in an explicit grant of authority from Congress in the statutory code.
If a statute written decades ago failed to anticipate a novel mechanical innovation, regulators have no power to stretch the literal text through expansive interpretation, no matter how lethal that invention proves to be. Extreme danger may underscore the urgency for action, but it does not conjure lawful executive authority out of thin air.
Under the American constitutional architecture, legally banning a dangerous weapon requires clearing three distinct, independent hurdles. The first hurdle is statutory definition by Congress. All administrative regulation must originate from statutory law. In the federal statutory definition of a machine gun, Congress explicitly defined a machine gun as any weapon that shoots, is designed to shoot, or can be readily restored to shoot, automatically more than one shot, without manual reloading, by a single function of the trigger. Crucially, any part designed and intended solely and exclusively for use in converting a weapon into a machine gun is itself defined as a machine gun.
The second hurdle is administrative interpretation by law enforcement. The Bureau of Alcohol, Tobacco, Firearms and Explosives (ATF), an agency within the Department of Justice, is responsible for regulating the firearms industry and enforcing federal gun laws. The ATF holds no legislative power of its own; it can only issue interpretative rules based on statutory language passed by Congress.
The third hurdle is judicial review by the courts. The federal judiciary, culminating in the Supreme Court, possesses final authority to determine whether an administrative rule exceeds statutory authority. Any citizen who believes an executive regulation lacks a statutory basis can challenge the government in court.
The effort to ban bump stocks ran the full gauntlet of these three hurdles.
In the aftermath of the Las Vegas tragedy, the ATF, directed by the White House, issued a formal rule in 2018 classifying bump stocks as illegal machine guns, ordering owners to destroy or surrender them within a specified window. However, Michael Cargill, a gun shop owner from Texas, challenged the regulation in court. In June 2024, the Supreme Court ruled 6–3 that the ATF had exceeded its statutory authority, invalidating the ban. The Court explained that when a bump stock is installed on a rifle, the entire firearm reciprocates during firing, causing the trigger to bump against the finger repeatedly; because the trigger must release and reset between each shot, it does not meet the physical definition of firing multiple rounds by a “single function of the trigger.” Writing for the majority, the Court held that amending the law is the responsibility of Congress, and administrative agencies may not unilaterally expand statutory definitions.
The ball was thus punted back to Congress. Just four days after the Supreme Court’s ruling, Senate Democrats sought to pass a statutory ban on bump stocks using the unanimous consent process. Under this Senate procedure for uncontroversial measures, legislation can bypass floor debate and pass immediately, provided no single senator objects.
However, a Republican senator from Nebraska raised an objection. That lone dissent instantly closed the expedited legislative track, leaving the bill indefinitely shelved.
Following this sequence of events naturally raises two fundamental questions: Why are statutory definitions so easily circumvented by mechanical ingenuity? And if public consensus is so overwhelming, while gun manufacturers do not even depend on these accessories for profit, why does Congress persistently fail to amend the law?
The inherent flaw of statutory law is that static statutes written decades ago cannot foresee evolving mechanical engineering. When Congress drafted the phrase “single function of the trigger” in 1934, lawmakers had in mind traditional machine guns where the trigger is pulled and held down; they could not fathom that future inventors would harness recoil and sliding stocks to match machine-gun firing rates while mechanically releasing and resetting the trigger on every single shot. In the eyes of judges adhering to strict textualism, this design successfully exploited a statutory loophole.
What happens, then, when a statutory definition is entirely airtight? That brings us to another case: the Glock switch. This conversion device works by depressing the firearm’s internal disconnector, converting the handgun directly from semiautomatic to fully automatic fire. Under federal law, there is zero ambiguity: the switch itself qualifies legally as a machine gun. Simply possessing an uninstalled piece of metal switch constitutes a federal felony.
Yet why are these switches everywhere? Because decentralized manufacturing technologies have completely overwhelmed traditional enforcement networks. The original patent expired in 2016, entering the public domain. Measuring no larger than a coin, these devices easily evade interception in international mail, and anyone with a consumer 3D printer can fabricate one at home. No matter how flawless a statutory definition may be, it cannot stop underground manufacturing distributed across thousands of households. Law enforcement capacity is stretched past its breaking point.
Why, then, does Congress refuse to amend the law? The common intuition points to lobbying dollars from firearm manufacturers. Over the past two decades, gun rights organizations have spent more than $230 million on federal lobbying—six times the $37.1 million spent by gun control groups. Yet when it comes to full-auto conversion devices, gunmakers are not the primary culprits blocking reform. Legitimate manufacturers derive their core profits from standard handguns and semiautomatic rifles; cheap aftermarket accessories are not financial pillars. In fact, mainstream manufacturers fear that controversy over these devices will trigger a broader wave of gun control legislation. The NRA’s voluntary call to regulate bump stocks in the wake of the Las Vegas shooting is clear proof of that dynamic.
The true cause of congressional paralysis lies in the defensive calculus of polarized politics. In the Senate, ending debate and advancing a bill to a final vote requires a 60-vote supermajority to invoke cloture and overcome a filibuster. Conservative lawmakers harbor genuine fears of a slippery slope: once statutory language is reopened, gun control advocates could seize the opening to attach restrictions like magazine capacity limits. Held captive by the primary election system, moderate lawmakers who vote to compromise risk being purged by primary challengers from the extremes. Meanwhile, the political cost of obstruction is practically zero. With such a low threshold for the minority to exercise veto power, even legislation backed by 80% of the public can be effortlessly derailed by one or two determined lawmakers.
Looking back at the entire saga surrounding full-auto conversion devices, there is no grand conspiracy to uncover. Throughout this ordeal, every participant rationally pursued their agenda according to established legal rules: the public demanded safety, the White House proposed solutions, law enforcement pushed forward regulations despite institutional headwinds, the Supreme Court upheld the literal meaning of separation of powers, and even gun lobby groups briefly stepped back.
Yet when all these compliant gears meshed together, they produced a deadlock that no one could untie. By design, this system prioritizes procedural safeguards against executive overreach over sheer operational efficiency. It decentralizes veto power across every branch, allowing almost any player to slam on the brakes. The legislature remains paralyzed by partisan polarization; executive efforts to step into the void are struck down by the courts for overreach; and when the judiciary punts the issue back to Capitol Hill, a determined minority can effortlessly kill the bill.
Danger does not vanish simply because procedural rules are scrupulously observed. In this endless loop, every actor stands on solid procedural ground, while the conversion devices capable of unleashing fully automatic fire continue to slip through the institutional cracks and circulate in the real world.
EN_TITLE: Why the US Can’t Ban Fully Automatic Weapons EN_DESCRIPTION: Despite presidential orders, overwhelming public support, and rare NRA concessions, the US failed to ban rapid-fire conversion devices. The real roadblock was not a gun lobby conspiracy, but a constitutional design of checks and balances that prioritizes procedural limits over legislative efficiency.