Three years ago, a federal ban on "bump-stock-type devices" took effect, transforming otherwise law-abiding owners of such firearm accessories into felons overnight. Despite its severe and startling consequences, that ban was never approved by Congress. It was unilaterally imposed by the Trump administration, which expanded the statutory definition of "machinegun" to include bump stocks and rifles equipped with them. As the Firearms Policy Coalition (FPC) explains in a brief it recently filed with the U.S. Court of Appeals for the 5th Circuit, that redefinition "defies any recognizable public meaning of the language of the statute and leads to absurd results."
Even if you have no interest in bump stocks or firearms generally, this case poses a question that should concern anyone who values the rule of law and the separation of powers. Can an administrative agency—in this case, the Bureau of Alcohol, Tobacco, Firearms, and Explosives (ATF)—rewrite a statute to accommodate a president's policy preferences by criminalizing previously legal conduct, or is that authority reserved to the legislative branch?
Bump stocks, which became suddenly notorious after they were used in the 2017 Las Vegas massacre, facilitate a rapid-firing technique in which the shooter, after pulling the trigger, pushes the gun forward against his stationary trigger finger. The recoil resets the trigger, which repeatedly bumps against the finger because of the forward pressure. Prior to the federal ban, the leading manufacturer of bump stocks was Slide Fire Solutions, which sold a stock replacement that allowed the front part of a rifle to slide backward after each round, resetting the trigger. Crucially, a bump-fired rifle still discharges just one round each time the trigger is activated, and the technique does not require any particular accessory.
The first point is crucial because federal law defines a machine gun, which is more strictly regulated than a semi-automatic firearm, as "any weapon which 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." (The definition also includes "any part" or "combination of parts" that is "designed and intended for use in converting a weapon into a machinegun.") And as the FPC notes, treating a bump-fired rifle as a machine gun implies that "nearly every semiautomatic firearm in existence" could fall into that category.
The ATF tried to get around the first obstacle by portraying bump firing as "automatic," even though it depends on the shooter's ongoing intervention. Unlike a machine gun, a bump-fired rifle does not shoot continuously when the trigger is activated. The trigger has to be reset before the gun can fire again, and it fires additional rounds only as long as the shooter continues to push the weapon forward and keeps his trigger finger in position. The ATF glossed over those facts by treating the shooter as part of the mechanism.
"ATF's definition of 'automatically' redefines that term as not merely self-acting, but also as encompassing the far broader and malleable category of a self-regulating function that includes ample manual input," the FPC notes. "And it interprets the phrase 'by a single function of the trigger' as covering only the initial function in a series of multiple functions of the trigger."
The ATF tried to escape the logical implications of that view by arbitrarily limiting it to situations in which the rifle is equipped with a "bump-stock-type device." But as the ATF conceded, 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." Why doesn't a bump-fired rifle qualify as a machine gun in those circumstances? Only because the ATF said so.
"ATF has failed to cogently explain why the [new] definitions do not apply to all weapons that can be bump fired and to all combinations of everyday items that can ease or facilitate bump firing," the FPC notes. "Because each subsequent function of the trigger is not dependent on how the trigger finger is kept fixed and independent of the forebody, ATF's new definition would apply to any weapon that can be bump fired, and any mechanical assist that could be combined with a semi-automatic weapon to make such firing technique easier. Thus, nearly every semiautomatic firearm in existence would be defined as a machinegun, ATF's arbitrary and irrational denials of that consequence notwithstanding."
Before February 2018, when then-President Donald Trump announced that he planned to ban bump stocks by administrative fiat, the ATF had repeatedly said, based on the plain meaning of the statute, that guns equipped with them were not machine guns. By the FPC's count, the ATF affirmed that conclusion in "ten different letter rulings."
The ATF initially applied the same analysis even to the Akins Accelerator, which included a spring that used recoil energy to reactivate the trigger by pushing it against the shooter's finger. In 2006, the ATF reversed itself, saying that added component made the mechanism "automatic." But it continued to take the position that bump stocks without springs were legal.
In a 2017 case quoted in the FPC's brief, for example, the ATF noted that 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" (emphasis added).
That position made sense, the FPC argues, since "a bump stock does nothing to alter the physics of bump firing or the ability of any semiautomatic weapon to be bump fired in precisely the same 'self-regulating' manner initiated by the 'initial' bump of the trigger that [the ATF now] claims occurs with ordinary bump stocks. All an unsprung bump stock does is provide some play between the forward portion of the firearm and the stock so that the recoil of any given shot can, depending on the amount of forward pressure being applied by the shooter, cause the forebody of the weapon (and hence the trigger) to slide backward and away from the trigger finger that remains unaffected by the recoil, thus releasing the trigger. It does not use that recoil to then re-engage the trigger; the shooter herself must add additional manual input. Without such input, no further shots would be fired."
Despite the obvious problems with the ATF's new statutory interpretation, a three-judge 5th Circuit panel upheld the bump stock ban last December. The court rejected the argument that "automatically" means "completely without manual input," accepting the ATF's claim that it means "functioning as the result of a self-acting or self-regulating mechanism that allows the firing of multiple rounds through a single function of the trigger." And the panel concluded that "a single function of the trigger" can reasonably be read to mean a single pull of the trigger, excluding the subsequent bumping of the trigger.
In June, the 5th Circuit vacated that panel decision, and it is now reconsidering the case. The ATF's new, presidentially dictated understanding of "automatically" and "a single function of the trigger" is so implausible and counterintuitive that it seems clear the agency's ban has no basis in law. Whether or not you agree with Trump that banning bump stocks was a good idea, the Constitution does not authorize the executive branch to impose such a policy without congressional approval.