D.C. Circuit Upholds the Bump Stock Ban, Saying It Is Consistent With the 'Best Interpretation' of the Law

It is hard to see how, given the contortions required to deliver the unilateral prohibition that Donald Trump demanded.

The U.S. Court of Appeals for the D.C. Circuit yesterday upheld the federal bump stock ban that took effect in 2019, approving the legal contortions required to justify it. In blessing the Trump administration's redefinition of machine guns to include bump stocks and firearms equipped with them, the appeals court did not merely defer to regulators' interpretation of an ambiguous statute. It concluded that the new reading of the law—which contradicts the position that the Bureau of Alcohol, Tobacco, Firearms, and Explosives (ATF) consistently took before then-President Donald Trump demanded that the agency ban bump stocks by administrative fiat—is "the best interpretation of the statute."

That is hard to believe. The ATF's justification for the ban is so implausible that it seems clear the agency rewrote the law to accommodate the president's policy preferences, criminalizing previously legal conduct without bothering to seek new legislation from Congress.

Bump stocks, which became suddenly notorious after they were used in the 2017 Las Vegas massacre, facilitate a rapid-firing technique in which recoil energy pushes the weapon backward, resetting the trigger, while the shooter maintains forward pressure on the gun, causing the trigger to bump against his stationary finger. Crucially, the gun still fires just one round each time the trigger is activated, and it continues to fire only as long as the shooter deliberately and repeatedly engages the trigger by pushing the weapon forward.

Those points are crucial because federal law defines a machine gun as a weapon that "automatically" fires more than one round "by a single function of the trigger." The definition also includes "any part" or "combination of parts" that is "designed and intended" to convert a firearm into a machine gun.

A rifle equipped with a bump stock, which allows the front part of the weapon to slide back after each shot, does not fire more than one round for each function of the trigger, which has to be reset and reactivated before the gun will fire again. Nor does a bump-fired rifle shoot "automatically," since the technique requires the shooter's active, ongoing intervention.

As the ATF explained the year before it imposed the ban, bump firing "requires the shooter to manually pull and push the firearm in order for it to continue firing." It added: "Generally, the shooter must use both hands—one to push forward and the other to pull rearward—to fire in rapid succession. While the shooter receives an assist from the natural recoil of the weapon to accelerate subsequent discharge, the rapid fire sequence in bump firing is contingent on shooter input in pushing the weapon forward, rather than mechanical input, and is thus not an automatic function of the weapon."

The ATF took that position for years, reaffirming it in a series of advisory letters. But in 2018, after Trump said he planned to unilaterally ban bump stocks, the agency suddenly decided it had misread the law. It accomplished the result that the president wanted by defining "a single function of the trigger" as a single pull of the trigger, thereby excluding the subsequent bumping, and by defining "automatically" in a way that ignored "shooter input."

While critics of the ban view those definitions as puzzling at best, the D.C. Circuit concluded that they are consistent with the plain meaning of the statute. How so?

Judge Robert Wilkins, who wrote the opinion for a unanimous three-judge panel, cites a 1994 case in which "the Supreme Court referred to an 'automatic' or 'fully automatic' weapon under the National Firearms Act as one 'that fires repeatedly with a single pull of the trigger,' in contrast to one 'that fires only one shot with each pull of the trigger.'" Wilkins is quoting a footnote that begins this way:

As used here, the terms "automatic" and "fully automatic" refer to a weapon that fires repeatedly with a single pull of the trigger. That is, once its trigger is depressed, the weapon will automatically continue to fire until its trigger is released or the ammunition is exhausted.

That second sentence makes it clear that the Court was using pull as shorthand for activating the trigger. That can be accomplished by pulling or bumping, and either way the trigger is "depressed." Unlike the gun at issue in that case, a bump-fired rifle does not "automatically continue to fire until its trigger is released or the ammunition is exhausted." Its trigger must be "released" before it can fire again.

Wilkins also quotes 1934 congressional testimony concerning the National Firearms Act by Karl T. Frederick, president of the National Rifle Association, who said "the
distinguishing feature of a machine gun is that by a single pull of the trigger the gun continues to fire as long as there is any ammunition in the belt or in the magazine." Again, it is natural to say pull in this context, since that is the way a trigger typically is activated. Frederick's use of that term hardly means that "a single function of the trigger," as used in the current version of the law, excludes bumping.

If the ATF were right that only a literal pull of the trigger counts as a "function," that would mean there is no "function of the trigger" when someone activates it in an unusual way (with a stick, say). When the trigger is pressed, whether by pulling it with a moving finger or by pushing it against a stationary finger, that surely counts as "a function of the trigger."

In a 2021 dissent, 10th Circuit Chief Judge Timothy Tymkovich explained why the ATF's distinction between pulling and bumping makes no sense:

The statute's plain meaning unambiguously excludes bump stocks. A
semiautomatic rifle, equipped with a bump stock, does not fire multiple shots by a single function of the trigger. "The trigger on that type of rifle must necessarily
'pull' backwards and release the rifle's hammer…every time that the rifle
discharges….The rifle cannot fire a second round until both the trigger and
hammer reset." Every shot requires the trigger to go through this full process again. The fact that a bump stock accelerates this process does not change the underlying fact that it requires multiple functions of the trigger to mimic a machine gun.

The ATF's understanding of "automatically" is likewise counterintuitive. After reversing itself in 2018, the agency now claims "automatically" means "the result of a self-acting or self-regulating mechanism that allows the firings of multiple rounds." As the ATF sees it, the shooter is part of that mechanism, which allows the agency to ignore the actions he must take to fire the gun repeatedly.

Wilkins says automatically "speaks of a mechanized process that requires less human exertion than an activity 'usually done by hand.'" But bump firing is "done by hand," as the ATF explained in 2017: "Generally, the shooter must use both hands—one to push forward and the other to pull rearward—to fire in rapid succession."

Wilkins is unimpressed by the argument that the need for those human actions means the gun is not firing "automatically." After all, he says, even "a prototypical machine gun" will not continue to fire unless the shooter keeps his finger on the trigger. But the legal definition of a machine gun hinges on what happens when the trigger is pressed, not what happens when the trigger is repeatedly pressed, released, and pressed again. When additional actions are required to fire additional rounds, the process is not automatic.

"If a shooter pulls the trigger of a semiautomatic rifle equipped with a non-mechanical bump stock without doing anything else, the rifle will fire just one shot," Tymkovich noted. "To make the firearm 'shoot automatically more than one shot,' the shooter must also be pulling forward on the barrel of the gun. Because a bump stock requires this extra physical input, it does not fall within the statutory requirement that the weapon shoot 'automatically…by a single function of the trigger.'"

Wilkins is also unfazed by the fact that bump firing does not require any particular accessory. As the ATF concedes, bump firing is a "technique that any shooter can perform with training or with everyday items" such as "rubber bands, belt loops, string, or even people's fingers." The agency nevertheless says bump-fired rifles are not machine guns unless they are equipped with a "bump-stock-type device." Wilkins thinks that distinction makes sense because bump firing is harder without such an accessory:

Plaintiffs' fear that all semiautomatic weapons will be subject to regulation because they can be modified with everyday items, like belt loops, to fire automatically is unfounded. Unlike a bump stock, a rubber band or belt loop is not automatic because it is not self-regulating. Rather than harnessing the firearm's recoil energy from a rubber band or belt loop in a linear path to engage in a continuous firing sequence, the shooter must harness and direct the recoil energy himself….Harnessing the recoil energy without an automatic device requires a great deal of skill and renders it exponentially more difficult to bump fire.

Wilkins sees eye to eye with the three-judge 5th Circuit panel that upheld the bump stock ban last December. Like the D.C. Circuit panel, it said "bump stocks qualify as machine guns under the best interpretation of the statute." But the 5th Circuit vacated that panel decision in June, and it is now reconsidering the case. If the full court goes a different way, the circuit split could prompt the Supreme Court to weigh in.