Here’s Why ATF Approved Bump Stock But Not AutoGlove

The Autoglove. The ATF recently said it’s a “machine gun.” (Photo: AutoGlove/Facebook)

Bump stock. AutoGlove. What’s the difference? Both accessories, as  we’re told by industry folk, “simulate full auto fire.” The ATF classified the former as a “firearm part” and the latter as a “machine gun.”

What gives? Is the ATF playing favorites? Is the agency failing to do its job by not classifying the bump stock a machine gun, as NRA executive vice president Wayne LaPierre intimated in a recent interview on CBS News?

Not that I’m in the business of defending the ATF, but when it comes to the determination of the legality of the bump stock versus the AutoGlove it’s a no-brainer. ATF made the proper call.

Let me back up and say by “proper call” I don’t mean the right call. The right call is to acknowledge that the National Firearms Act is a sham. That it should be fully repealed. That it’s an infringement on our Second Amendment.

But that’s a convo for a different day. What I’m talking about today is the decision the ATF made based upon an honest reading of existing regs and established precedent with respect to similar devices.

I’m not an attorney. And I don’t work for the ATF. You can take my opinion with a grain of salt. But I can read. And I have read both determination letters (here and here) and, in my humble opinion, the ATF reasoning on both products is sound.  As always, feel free to tell me I’m wrong in the comment section.

What is a Machine Gun?

Before we get at it, let’s start with an obvious question.  What is a machine gun?  Under the National Firearms Act, per 26 U.S. Code § 5845, a machine gun is defined thusly:

  • 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 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, or
  • 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.

Bump Stock is Legal

Good old Mr. bump stock. NRA believes he should be subject to “additional regulations” because, as LaPierre said in that CBS interview, “It’s illegal to convert a semiautomatic to a fully automatic.”

The notorious bump stock. It’s a “firearm part,” according to the ATF.

ATF wrote in 2010, in response to Slide Fire’s submission, “The stock has no automatically functioning mechanical parts or springs and performs no automatic mechanical function when installed.”

“In order to use the installed device, the shooter must apply constant forward pressure with the non-shooting hand and constant rearward pressure with the shooting hand,” it continues. “Accordingly we find that the ‘bump-stock’ is a firearm part and is not regulated as a firearm under the Gun Control Act or the National Firearms Act.”

The main takeaway is that there is no automated firing. The shooter’s index finger is still technically doing the work, though it’s aided by the inertia (or recoil) of the gun thanks to the sliding of the bump stock. Consequently, it’s a part — not a machine gun.

AutoGlove’s TAD is a Problem

AutoGlove fails the smell test from the outset. It’s called the AutoGlove for Christmas’ sake. Okay, it shouldn’t be judged by its name alone. How does this device work?

The AutoGlove functions with the help of an electronically powered Trigger Assist Device (TAD). Users rest this TAD against the trigger, push in a plunger to active the TAD, and the paddle part of the TAD contacts the trigger and rapid-fire commences.

Part of the problem with the AutoGlove is that it’s TAD “replaces” the traditional trigger of the gun. (Photo: AutoGlove/Facebook)

Because the AutoGlove uses electricity it immediately raises a red flag. ATF has ruled on three separate occasions that electrically-driven trigger devices are machine guns. Once in 1982 and twice in 1988.

ATF makes another very important point regarding triggers. After a long legal paragraph defining the term “trigger,” it states, “In both practical and legal terms, the ‘trigger’ of a firearm is whatever is used to initiate the firing sequence.”

When the AutoGlove is used on a firearm the TAD — not the trigger — initiates the firing sequence. It’s now the mechanical element that gets the ball rolling. The conventional trigger of the gun becomes a subordinate part of the firing sequence.

By comparison, the bump stock does not replace the trigger. Not at all. Like any other semiautomatic firearm, one’s finger engages the trigger and the trigger initiates the firing sequence.

Does that make sense?  Clear as mud?

The AutoGlove is a Machine Gun

In this one sweeping paragraph, the ATF seals the fate of the beloved AutoGlove.  Once you read it, it’s hard to argue that the agency missed the mark.

Electronically-driven trigger devices are considered “machine-guns” because they are a “combination of parts designed and intended, for use in converting a weapon into a machine gun. Because these electronic devices use a switch/button to activate the drive motor to initiate the firing sequence, that switch/button is the firearm’s trigger. Since the weapon firearms more than one round for each single function of its trigger (a single press on the AutoGloves’ Activator Plunger), it would be a “machine-gun” as defined.

Let me unpack that.  The quote ATF refers to in the first sentence is part of the definition of a “machine gun,” as highlighted above.  The second sentence relates to the trigger issue I explained. And the last sentence again refers to the definition of a “machine gun.”

So, it’s a machine gun because it is a part that is designed to convert a semi-auto into a full auto, because it has an automated trigger system that when activated fires more than one round for a single function of the trigger.  Remember, the TAD initiates the firing sequence (not the conventional trigger) and when it’s activated, when the plunger is pushed down, it has the capacity to continuously fire rounds.

Sounds like a machine gun to me.  Per the law.

Hold the Phone!

Wait a minute!  Doesn’t the bump stock check the first box?  Isn’t it a “part designed and intended solely and exclusively… for use in converting a weapon into a machine gun”?

You may have been thinking this all along. But thanks, in part, to a smart play by Slide Fire, the inventors of the original bump stock, it doesn’t apply.  See, Slide Fire told the ATF that the part was “intended to assist persons whose hands have limited mobility to ‘bump-fire’ an AR-15 type rifle.”

Bump firing is not illegal. Bump fire is simply harnessing the recoil of a semiautomatic rifle to fire shots in rapid succession.  But it’s still one trigger pull for every shot fired.

The bump stock, which aids in this lawful way of operating a semiauto firearm, is not a machine gun.

The Last Salvo for AutoGlove

The AutoGlove does not permanently affix to the rifle, but ATF says that’s “immaterial.”  It doesn’t matter. (Photo: AutoGlove/Facebook)

The makers of the AutoGlove tried to get around the pesky NFA with two additional arguments.  The first was that the AutoGlove isn’t permanently affixed to the firearm.  It’s a glove!

The second was that the TAD needs to be ever so slightly pulled towards the trigger to activate the firing sequence.  This “micro-trigger” pull, as they called it, means that without additional human interaction the gun does not discharge.

ATF shot down both arguments.  The agency said that “not being permanently affixed to the firearm” doesn’t matter. It’s “immaterial.” Nowhere in the definition of machine gun is it spelled out that the device has to be “permanently attached.”

SEE ALSO: ATF to Suspend ‘Green Tip’ Ammo Ban, Reclassification

For the second point about the micro-trigger pull, the ATF tested the AutoGlove and found that, well, it worked without additional human interaction. That little micro pull wasn’t necessary to get the gun to fire once the TAD was placed within the trigger guard.

ATF said that, during testing, they even put forward pressure on the TAD to try to keep it away from the traditional trigger but there was still enough contact, and the rifle fired “continuously until the ammunition supply was exhausted.”  The test was repeated multiple times with the same results.

Oh, no.


You may be sitting back in your chair thinking that this is all just a bunch of hooey.  I don’t disagree with that assessment.  Both products should be lawful.  As mentioned, I believe the NFA is a sham.

You may also be thinking that while the ATF may have interpreted the law fairly in this instance, it’s still an agency that defaults to the political whims of the current administration.  I don’t disagree with that either.  Under Obama, the ATF sought to “reclassify,” aka ban, green-tip ammo.  Under Trump, earlier this year, someone from the ATF leaked a “white paper” that voiced support for suppressor de-regulation and the importation of M1 Garands.

Until the ATF disbands, which probably will never happen, they are the devil we have to dance with.  I think it’s best to reserve our criticism for them when they overreach or mess up, not when they do the job they’ve been tasked with.

About the author: S.H. Blannelberry is the News Editor of GunsAmerica.

{ 30 comments… add one }
  • Rollin L December 23, 2019, 3:30 pm

    When all this bump stock ban nonsense started, I instantly remembered the AutoGlove denial. Key to that is the concept that the “trigger” has been relocated in the operation of the firing sequence. It is now an electric button, not the mechanical trigger. And, indeed, no other human interaction is required. Fair enough.

    Now, the bump stock essentially fixes the trigger finger. If you fire a bump stock either one handed, or with a limp support arm and just initiate firing with the trigger finger, it will not function properly. It merely fires semi auto. The key is the individual movement from the support arm for each shot. Recoil does not really come into play, in my opinion. All recoil does in the context of bump stock function is the same thing it does on ANY firearm. It pushes the firearm and shooter back. Basic Newton here.

    I have never fired a bump stock. However, I have bump fired with the old belt loop method. In my experience, the firing is initiated by pulling the gun forward against the fixed trigger finger, not pulling the trigger like on a semi. I believe this is the same for the bump stock. Given the reassignment of the “trigger” in the AutoGlove model, I think a similar argument can be made for the bump stock. The off hand, support arm that pulls the gun forward is the real trigger actuation, and that must be done manually for each individual shot. The device will not work any other way. That the technique shortens the time required to reset and pull the trigger again, creating the “appearance” of increased cyclic rate, is immaterial. ATF has signed off on bump firing as a technique. So maybe some lawyers more clever than I can make use of the argument of what the “trigger” actually is on the bump stock-configured semi auto. Using ATF’s AutoGlove argument may work against them in this case. Or maybe I am nuts. It’s just a different way of looking at the issue.

    And it’s important to remember the cyclic rate of the firearm is NOT changing. The gun can cycle only as fast as its mechanical properties allow it to. It is only the human interaction that is sped up by bump fire, with or without the help of a device such as the bump stock. So what they are banning here is a device that- just as Slide-Fire submitted- is merely an aid to the limits of a particular human body. We can’t all be Jerry Miculek, right? Why should HE have all the fun!

  • willie February 4, 2018, 10:09 pm

    i find the whole argument/worry about ‘bump stocks’ very funny – as any experienced shooter knows, you don’t need a bump stock to make a semiauto rifle act like an auto – it’s all in the trigger and stock handling

    • William Snead May 13, 2019, 4:20 am

      Very true and with a little searching you can find all that information on the internet. I wrote the President that why would I buy a bump stock when rubber bands are cheaper

  • billybob November 14, 2017, 8:27 pm

    Life Member of the NRA ! The ship for brains had no problem throwing Machine Guns under the buss in 1986 even throw no crime has ever been committed with them by there lawful owners ! Cheapest MG now sale for $7000 plus dollars ! Bump stocks let people enjoy the thrill without going broke ! 4473 . Lying on this form is a felony and can be punished by up to five years in prison Question 11.e: Added a warning statement regarding marijuana that has been legalized or decriminalized for medicinal or recreational purposes in the state where the transferee/buyer resides. Instruction for Questions 11.b – 12 (Formerly Questions 11.b – 11.l): Added a new paragraph between the 1st and 2nd paragraphs. “A member of the Armed Forces must answer “yes” to 11.b. or 11.c. if charged with an offense that was either referred to a General Court Martial, or at which the member was convicted. Discharged “under dishonorable conditions” means separation from the Armed Forces resulting from a dishonorable discharge or dismissal adjudged by a General Court-Martial. The term does not include any other discharge or separation from the Armed Forces.” / EVERY LAW PASSED IS ONE LESS FREEDOM YOU HAVE !

  • Carl November 13, 2017, 2:12 pm

    The NRA is just wrong, and I feel betrayed by them. I bought a surefire because it was ATF approved. Well now the nut jobs have come out of the woodwork to ban a chunk of plastic and the NRA joins them, W T F. Anybody want to buy a $300.00 paperweight, thanks a lot NRA I won’t be renewing.

  • Joey Nichols October 30, 2017, 1:25 pm

    Good article. Agree NFA = infringement; enough said, get rid of it.
    Question would AutoGlove be “legal” if actuating device were only on back of finger/hand and flesh was only touching firearms’ trigger?

  • Tom Benton October 29, 2017, 1:28 pm

    There are at least 100 ways to skin a cat and I bet just as many ways to manipulate firing a weapon to simulate automatic fire.
    I distinctly remember watching Jerry Miculek shoot an AK 47 clone semi auto vs a true AK47 for speed. At the end of a magazine, Jerry was only thousands of a second slower using his magic fnger vs a true autmatic weapon. Maybe the ATF should ban Jerry. !
    That said, I have never understood the fascnation of automatic weapons for the cvilian population. Automatc fire is inherently inaccurate particularly for those unable to practice frequently. Additionally, ammunition is expensive. But most importantly, unless you have supply logistics, you will exhaust your ammunation with automatic fire. A firearm without ammunition is a club. If you are depending on your firearm in a time of crisis to defend your life, you have lost the battle when your ammunition is expended. I occasinally burn through a 30 round magazine on an AR. I do thto make sure I can hit an 8” steel target at 100 yards with each round. If my rate of fire results in misses, I fired too fast as I know I can acheive 100 % with proper timing. The bullet you need to save your life or the lives of your family may be the last one in the magazine. Make sure you still have it.
    Oh, regarding the idiots in Congress demanding a limit to magazne capacity, I ask this question. If 3 armed men invade your home , how many rounds do you want in your weapon ? As many as you can load.

  • Will Drider October 28, 2017, 2:16 am

    The ATF is using two different standards of logic on the two devices! Read the bump stock approval Letter. Then read the AutoGlove denial, digest how they classify “trigger” and apply it to the bump stocks. They declare the button on the AutoGlove is the actual triggering mechanism that initiates the firearms firing cycle and the integeral trigger on the firearm is a sub-part. Press the button and the firearm will fire multiple cartridges until empty. Now hold that thought!
    The Bump Stocks: The operators hand pushes forward on the fore end “initiating the firing cycle” while the other hand pulls the shoulder stock back and the operators “static finger” placed on a designed Rest: the initiating firing pressure caused the firearms sub-part integral trigger to contact the statioary finger: firinf the firearm. The continuous forward pressure will a fire cartridges until empty. The finger on the rest doesn’t anatomically “pull” the trigger; it could be replaced with a straight wooden dowel and the function would be the same!

    Pess down the button or hold forward pressure = they are the both causing the initiating action to start cyclic firing and both make the firearms integeral trigger a “sub-part” per ATF logic. ATF also shot down the AutoGlove claim that minuscule movement of the trigger finger was required, the bump stock does not require any movement of the finger in the trigger guard and they designed/provided a Rest specifically to keep it from moving! How can one be a machinegun and not the other? Seems to me, BATFE’s application of technical standards and historical prior decisions are not equally applied.

  • Robert October 27, 2017, 8:27 pm

    So does that mean that sip triggers that many quadriplegics and other disabled individuals use for hunting and/or recreational shooting are technically a violation of the NFA? They are electrically driven trigger pulling devices after all….

  • David P October 27, 2017, 1:26 pm

    The ATF is never going away and NFA is never going away. Every time some smart a$$ designs another loop hole gizmo to fit through the cracks in a crappy law (bump stock, Black Aces DT, Mossberg shockwave, arm braces, Echo trigger) it makes it more likely that THEY will try to strengthen the NFA and less likely that WE can lighten it. We have fought hard to prevent reopening that can of worms. The fact that it is so flawed is what makes it tolerable The $200 tax stamp was intended to be a prohibitive amount, do you really want that reinterpreted to today’s standard .
    The use of a bump stock in a crime has killed any chance of the HPA/SHARE act ever being looked at again.
    When people (dumb a$$es) were all over youtube showing how arm braces are a legal way to skirt the law, using those exact words in the title of the video, that was the beginning of the end.

    So thanks, to all you people who thought flaunting the fact that you outsmarted a 85 year old law was a good idea.

    • Joey Nichols October 30, 2017, 1:34 pm

      Should we live in fear of displeasing our masters or should we show that we are free citizens, being infringed upon by a tyrannical government? I think I’ll fight them tooth and nail, and risk being called a smart a$$, in an effort to live as our founding fathers intended.

  • Frank J October 27, 2017, 11:36 am

    Here is a simple way to explain why ATF was correct on both the slide fire stock and the electric glove. If you have a legal (for now) trigger crank/cam activated device and you remove the crank handle and replace it with an electric screwdriver or a wind-up spring mechanism, you will be in violation of the National Firearms Act and in possession of an illegal machine gun.
    ATF is going to have to change the definition of a machine gun in order to make these devices illegal.

  • joefoam October 27, 2017, 8:34 am

    I don’t have a problem with the NRA deferring to the ATF on these issues, they were on the winning side of the argument. I do have a problem with the ATF in general, and the NRA has opposed them in the past. A stronger statement should have been issued instead of trying to duck the question.

    • Joey Nichols October 30, 2017, 1:43 pm

      The ATF goal should be, that these items (alcohol-tobacco-firearms) are so important to life in America, that they should be in the hands of every adult American citizen without restrictions.

      Unless, you feel that you are not responsible enough to handle them, then you may recind your rights, but please don’t infringe upon mine.

  • G-Man October 27, 2017, 7:09 am

    Has to subject of “Binary Triggers” come up yet?

    • Godfrey Daniel October 27, 2017, 12:29 pm

      Shhhh. Don’t make them aware of something they might not already know about.

    • Tyrone October 27, 2017, 1:32 pm

      Yes, I too (and a bunch of other folks) would like to know the answer to your question….

  • Jay October 27, 2017, 6:16 am

    The whole point to me in the rendering is this, the glove is a mechanical device, the Bump stock is not and you don’t need a Bump stock to bump fire, where the glove is solely a mechanical device! You can bump fire just about any semi auto long gun!

  • Blue Dog October 26, 2017, 4:33 pm

    Bump stocks still are an attempt to circumvent the NFA and simulate fully automatic fire from an otherwise semi-automatic rifle. While such products are inherently dangerous to both the user and the public, they are obviously supposed to be illegal under that same NFA. The same argument could apply to other accessories, most obviously braces to convert pistols into SBRs. Both products should be subject to regulation as firearms under the NFA and the over-the-counter availability of bump stocks and pistol braces and the obvious flouting of the law by gun owners across the nation shows the weaknesses in our lax gun laws, particularly when compared to other nations in the developed world. If the United States does not work to fix its gun violence problem – a problem that spills over its borders and makes other nations like Mexico more dangerous – then the UN should step up and enforce the Small Arms treaty of a few years ago.

    • Topol October 27, 2017, 7:25 am

      Did your parents have any children that lived?

      • Joey Nichols October 30, 2017, 1:51 pm

        My thought too.

        Or which socialist country are you representing and trying to convert America into? If those “developed “ countries are so great…….move there.

    • Mike V October 27, 2017, 7:39 am

      And by UN stepping in to enforce what do you mean explicitly? Spell it out patriot…

    • PA G October 27, 2017, 8:18 am

      You’ve been trolling this website by copying/pasting the same old tired anti-gun arguments over and over again. Nobody here is buying what you’re selling so stop wasting your time. Go back to your leftist, globalist hole where you came from.

    • Chuck Matson October 27, 2017, 10:43 am

      Get lost pink-o.

    • Tyrone October 27, 2017, 1:27 pm

      Hahahahahah… Your post not only doesn’t pass the smell test, it is woefully slanted to a variety of falsehoods that are totally without merit and have been proven wrong. 😀

    • Danny October 27, 2017, 6:28 pm

      The un should not stick its nose into our affairs. The NFA is illegal and should be done away with! If you as an American can’t stand to live in a free country you should try living in one of those other countries that you think are so great and see what you think is a great way of life! Don’t let the door hit your sorry but on the way out!!!!

    • Chauvin Emmons October 29, 2017, 3:32 am

      beg your pardon What part of Shal not be Infringed dont you understand comrade.
      Thank GOD for laws common sense is not so common even for the common.
      Best we just remove all warning labels and let nature take its course

    • E.P. October 30, 2017, 1:44 pm

      “shows the weaknesses in our lax gun laws, particularly when compared to other nations”.
      What makes you think that Americans give a hoot about what other nations do? Leftist are always trotting out that same argument … “every other nation believes in man-made global warming”, “every other nation believes in free health care”, “every other nation believes in Govt control of private wealth”, “every other nation believes in strict gun control”. We don’t give a crap about what other nations do precisely BECAUSE WE ARE AMERICANS.

    • canemah February 9, 2018, 6:12 am

      – then the UN should step up and enforce the Small Arms treaty of a few years ago.

      You lost the argument with that comment alone. Blue helmets make great targets.

    • MagnumOpUS November 23, 2018, 8:36 am

      F- the U.N.!

      It should be relegated to feeding the Third World’s poor.

      It should also be defunded by the U.S., and, if possible, be relocated to the West Bank.

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