A Single Function Of The Trigger

Not being a gun guy, it’s unclear to me what purpose a bump stock serves other than to allow someone to shoot a lot of bullets very quickly by using the rifle’s recoil to do the trigger pulling work. They are useful to people with disability, or so I’m told, though I’m not sure why and it doesn’t really matter. And after what happened in Vegas, I can well appreciate why bump stocks can present a horrific menace that should no more exist than machine guns in civilian hands.

Your mileage may vary, but I just can’t see any reason to allow the sale of bump stocks, other than to prepare for battle with…someone.

But that wasn’t the question raised in Garland v. Cargill, and almost every outraged critique of the decision deliberately ignores the rationale for the decision by presenting it as the ethically compromised conservative wing of the Supreme Court doing the bidding of its NRA masters. They chose bump stocks over the lives of Americans. There is much to criticize and challenge in Justice Thomas’ (of all people) opinion for the majority, but at least challenge it because of the flawed rationale, not because guns are evil and bump stocks make evil guns even more evil.

Bump stock devices were banned the next year, just as all fully automatic machine guns are banned for public use, but the six conservative members of the court seemed entirely unbothered by their deadly potential. The opinion, written by Justice Clarence Thomas, parses in a ridiculous level of detail whether bump stocks truly fit the precise mechanical definition of a machine gun. Because the court feels the need to give the greatest possible deference to the ownership of guns, however they might be used, the court concluded that they are not really machine guns, as they do not allow firing multiple rounds “by a single function of the trigger.”

That first line is correct but misleading. The issue was not whether bump stocks should be banned, but whether the Bureau of Alcohol, Tobacco and Firearms has the authority to ban them without specific enabling legislation under the definition of “machinegun.” While the subject matter at issue was bump stocks, the legal issue was about the authority of an executive branch agency making a bureaucratic decision to ban bump stocks under the authority of legislation banning machineguns.

The opinion, full of lovingly detailed close-up drawings of a gun’s innards (provided by the  Firearms Policy Foundation, a pro-gun nonprofit group), says nothing about the purpose of a bump stock. Why would someone buy the device and use it? Only to fire a lightning burst of rounds.

This is true, but is it relevant to the legal issue being decided? The question was not whether bump stocks were good, evil or double evil, but whether they fit within the definition of machinegun as crafted by Congress.

The term “machinegun” means 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 term shall also include the frame or receiver of any such weapon, any part designed and intended solely and exclusively, or combination of parts designed and intended, for use in converting a weapon into a machinegun, and any combination of parts from which a machinegun can be assembled if such parts are in the possession or under the control of a person.

The issue, and only issue, presented in Cargill is whether a bump stock meets this definition, thereby empowering ATF to ban it as a part enabling a semi-automatic to become a machine gun. The key phrase here is “by a single function of the trigger.” In other words, pull the trigger once and more than one bullet comes out.

The physics of a bump stock says that’s not how they work. The physics of not giving a damn about the physics of a bump stock when it comes to weapons that can be used for mass murder says who cares? It enables a shooter to fire hundreds of rounds a minute, and wasn’t that what Congress intended to forbid when outlawing machineguns?

But Justice Sonia Sotomayor, in a dissent laced with astonishment at what her colleagues had done, didn’t hesitate to explain what was really happening. “When I see a bird that walks like a duck, swims like a duck and quacks like a duck, I call that bird a duck,” she wrote, and in this case, the duck is an illegal machine gun.

The ATF had taken the position that a bump stock did not convert a semi-automatic rifle into a machinegun, until it didn’t. It didn’t change the way it walked, swam or quacked, but the ATF reversed itself because the bump stock enabled a shooter to kill 58 people in Vegas.

If Congress wanted to ban the bump stock at the time, it could have. Modifying legislation to adapt to change when its original definition no longer reflects its intent is one of the basic jobs of the legislative branch. It’s not the job of the executive branch, which has squeezed into Congress’ role to fill the gap created by disfunction and paralysis.

If saving lives matters more than the validity of rationales in the face of congressional failure, then this decision will break your heart. But if so, at least be honest about it and don’t fudge the truth to pull on the heartstrings of a nation.

24 thoughts on “A Single Function Of The Trigger

  1. Carlyle Moulton

    A bump stock allows the firer to pull the trigger many times very quickly without moving his finger.

    1. LY

      Which still does not fit the legal description of a machine gun.

      Even more so as true “machine guns” are belt fed bi or tripod mounted crew served squad level weapons. Pretty much every military in the world has moved away from full auto personal weapons simply because they burn through to much ammo and are to inaccurate at full-rate fire to be useful on the battlefield. Everyone switched to select fire 3-round burst weapons for individual carry decades ago.

      1. Bill Robelen

        The thing is, the U.S. military has gone back to the full auto function in its select fire assault rifles. This change occurred during the height of the war on terror, when they realized that having a full auto function for everyone was more useful than a three round burst during a rapid engagement. Originally three round burst was used because weapons with larger rounds such as the M-14 were not easily controlled after more than three rounds. Experience has shown that with the lighter rounds a M-4 or M-16 is controllable in longer bursts.

        1. SHG Post author

          Does this have anything to do with the post? If anyone feels the need to discuss this further, take it to reddit. It will be trashed here.

  2. LocoYokel

    The purpose of a bump stock is to burn through lots of ammo and money at the range.

    As a gun owner I can see the fun in this, as a not billionaire I can see that, while I would like to shoot one occasionally, I cannot afford to do so frequently.

    1. Hal

      Two comments I saw elsewhere on bump stocks, “They’re range toys for turning money into noise” and
      “They’re dumb and I wouldn’t take one if it fell off the back of a truck and landed at my feet”, (no link per rules) sum up my feelings.

      That said, they’re not machine guns. So, technically, SCOTUS decision makes sense. Whether they could be banned as destructive devices under same statute (1934 National Firearms Act), I don’t know.

      Ignorance, hoplophobia, and political convenience seem to drive legislation and judicial rulings on the RKBA.

      I really wish that Justice Kennedy had the integrity and testicular fortitude to agree that strict scrutiny was the appropriate standard of review when deciding Heller and returned case to DC courts. This would have been logical, consistent, and saved us the abortion that is Bruen.

      I wish I’d win the lottery, too.

  3. Dan

    It’s probably worth pointing out that machine guns are legal for civilian ownership and use in most of the US, so long as they were made before May of 1986. That date limitation has effects on the market that are entirely obvious to anyone with the most basic knowledge of economics (and also is bad news for the bump stocks, had the Court gotten this one wrong), but most of the country can buy, own, and shoot machine guns perfectly legally.

    1. L. Phillips

      And the NRA supported the bump stock ban when Trump first announced it, reversing themselves later on. And “civilians” can own automatic firearms from any date or time if they are willing to undergo the rigors of federal licensing.

      I love it when critics actually do real research. The article the Admiral quotes wasn’t one of those times.

  4. Michael King

    I suspect there is a fear that sustaining such a ban will trigger further bans by eroding a technical definition here reinterpreting definitions there, until arms in common use get banned.

    I support not infringing upon the 2nd Amendment, but am quite conflicted concerning bump stocks. Same-same forced reset triggers. These are Sotomayor’s ducks.

    Either remove restrictions on automatic weapon ownership or, like automatic weapons, license and record transfers of FRTs and bump stocks. I write this knowing rabid gun grabbers will try to leverage such into more general arms bans and others will hate me and call me un-American.

  5. Hal


    I’m not sure if this adds anything to the discussion, but FWIW I just heard an NPR pc on this decision.

    Somewhat surprisingly, as NPR tends not to get 2A/ RKBA, their summation of ruling and why it made sense was accurate.

    They then showed a certain ignorance by likening bump stocks to the “Glock switches” which actually do turn semi autos into machine guns. There’s little reason to think that this would somehow apply. These devices could/ should be illegal under 1934 NFA.

    They then went on to discuss “Ghost guns”, related only in that they’re guns and speculate about what happen w/ these. As firearms in the 18th and early 19th centuries didn’t have serial numbers, Ghost guns would likely be protected under Bruen.

    1. hal

      This AM NPR reverted to form. They had a law prawf on who said, at least three times, that with a bump stock an AR-15 could fire 500-800 rounds with “a single pull of the trigger”. His statement is not only incorrect, it demonstrates a great degree of ignorance of how firearms function.

      Further, he said something along the lines of “The court should consider what congress intended, not what the law says”.

      IANAL, but I’m pretty sure that what the law actually says is pretty important.

  6. KP

    ” They chose bump stocks over the lives of Americans.”
    Rubbish! A bump stock just allows you to shoot faster than without one, by some small amount..

    So?? Do you want to have people shoot slower? Are you up for banning semi-automatic (or self-loading) arms as well? Sending everyone back to bolt-actions? Why stop there, its slower again to muzzle-load, so lets really slow shooters down!
    Your mass shootings are just a by-product of your society, shooting faster is not researched by criminals and its benefits are designed for other people. However those who want to disarm a population are always keen to reverse any advance in shooting tech, as witnessed in NZ and Australia. The only people who have to fear an armed populace are Govts who will do things the populace will shoot them for.

    “a gunman using semiautomatic rifles equipped with bump stocks fired hundreds of rounds into a crowd in Las Vegas, Nevada, killing 58 people and wounding over 500 more”
    The real question is, ‘how many would he have killed with just semi-auto rifles’? If he was aiming, the answer would be ‘the same number’.

    1. Luke Gardner

      There is a willful ignorant on X who stated that the 2A applies only to muskets because that was the height of firearm technology at the time of it’s adoption (not true as it happens). The ignorant went on to further state that she could not imagine that the founders/drafters could themselves have imagined the advance of firearm technology to the point that semiautomatic firearms are a commonly used technology and that the founders would be horrified at the existence of such modern firearms. She plainly had either forgotten about or never read Art I, Sect. 8, Cl. 8. which clearly indicates that the founders did indeed anticipate advances in technology and encouraged them to boot.

  7. Hunting guy

    Austin Harleys [Ed. Note: Healey. Austin Healey.] are fun to drive. But they pollute the ground with oil leaks and cause global warming because they lack modern emission controls. They get in wrecks and people die as a result because they aren’t built to modern safety standards. Plus, they are expensive to repair and parts can be hard to obtain.

    Should we ban them?


    As others have said, bump stocks are fun and expensive, turning money into noise. Besides, I’ve seen videos where people have used rubber bands to provide the same functionality as bump stocks.

    Let people have their fun, like those that drive old cars they love.

    The SC got this one right.

  8. Bennett

    “If Congress wanted to ban the bump stock at the time, it could have.”

    Could it, though?

    If you were Congress, how would you write a law that banned devices that allowed multiple trigger actions without finger movement? You would want to write the law broadly enough that it would ban whatever method creative people might come up for the same purpose, without banning things that are in common usage for other purposes.

    1. phv3773

      How could Congress write a law? By quoting the existing law and adding language meaning, in effect, “including bump stocks”. They could write a law banning guns capable of firing over 100 rounds in a minute.

      1. Jay Bravo

        Thank you for proving Bennett’s point about Congress and poorly written laws.

        “100 rounds a minute”, on top of being an arbitrary number, would ban essentially every firearm made in the last 50 years and many before that, regardless of type, as the the limiting factor is usually the ammo capacity and the capability of the human, not the firearm. That’s less than 2 rounds a second, and manufacturing tolerances are tight enough that those firearms that can’t fire at that rate are the exception, not the rule. I can “tube dump” all eight rounds from my pump action shotgun in three seconds, well above the rate of fire you mentioned, and it’s basically off-the-shelf.

    2. Mike V

      So, Congress can’t figure how to define bump stocks as machine guns but bureaucrats at BATFE could?
      Granted, I think Congress is stupid, but they’re not that stupid.

    3. Keith

      Not that NJ should ever be used as a model when it comes to legislation, but they banned bump stocks (as well as trigger cranks and other fun accessories for the terminally bored and stupid) without making a dent in AR sales or other weapons that fly off shelves.

      Congress can legislate. They just forgot they didn’t delegate that power away to BATFE.

      (and yes, I had many other thoughts)

  9. Anonymous Coward

    As mentioned bump stocks and forced reset triggers are range toys for converting money into Moises. They exist because the Hughes Amendment made buying actual machine guns prohibitively expensive. Machine guns are legal to own, if you have the necessary NFA tax stamp.
    SHG’s reference to disabilities is actually about pistol braces, which are also subject to questionable and arbitrary rule making. Pistol braces are also mostly a workaround for regulation, specifically the NFA regulation on short barreled rifles.

  10. Keeping My Job

    Oh, no, and here I was hoping the “looks like a duck” test would end with Aereo. Can someone tell me how anyone can know ahead of time whether or not something will “look like a duck:” to the Supreme Court at some point in the future? Can the Supreme Court please come up with a test even more vague and unknowable than “looks like a duck”? I hope they can’t.

    The Aereo case had Aereo, Inc. going to extreme lengths to obey the law only to get creamed at the SC because “looks like a duck”. And here we have the dissent on the SC trying to ignore what the statute says because “looks like a duck” AGAIN.

    It’s nonsense.


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