In the wake of another horrific mass shooting incident in the USA which appears to have involved an automatic weapon I was surprised the read the following in the Weekly Standard:

Automatic rifles, on the other hand, are severely restricted and exceedingly rare.

While obtaining firearms for a typical civilian is relatively straightforward after applying for and obtaining a clean federal background check at a retailer, buying a full-auto firearm is incredibly difficult for a number of reasons.

I was surprised at this because there seem to be plenty of American gun enthusiast sites where what look to be automatic weapons are routinely demonstrated and it is certainly the impression from outside the USA that they seem to be common. But I'm not an American and I live in a country where even the police are not routinely armed so I might be basing my impression on inaccurate sources.

Is it very hard for an American to obtain an automatic weapon?

Note: I'm not asking about the recent incident or the accuracy of reports about it. Nor am I asking about gun control or anything to do with it. Just the facts about legal and practical access to automatic weapons in the USA (and, yes, the rules are different from state to state so include the facts on that if relevant).

  • 17
    Definitions may help: Semi-automatic=One trigger pull per bullet. Full-automatic=One trigger pull (and hold) releases bullets as fast as the gun can fire. The first is "relatively" easy to get, and while it may require a little more work, I think the distinction is almost academic between that and a full-auto (a machine gun). And there are many sites that advertise how to convert a semi to full auto too...
    – JasonR
    Oct 2, 2017 at 18:00
  • 13
    Add-on: Any weapon capable of semi can be "hacked" to full auto (with various degrees of effectiveness). This is especially true for "civilized" versions of military rifles that have the full-auto capability "taken away" -- usually through some modification of the trigger assembly (which is, obviously, reversible).
    – DevSolar
    Oct 2, 2017 at 18:19
  • 4
    @fredsbend True, that's why I suggested to shift the focus of the question to something less in need of interpretation. On the other hand, for quite a lot of people getting anything that costs 20k can probably be considered "very hard".
    – tim
    Oct 2, 2017 at 18:26
  • 3
    Those full-auto kits are generally deemed illegal as far as I know. However, that doesn't mean people with access to a machine shop or good tools can't make their own. I know I've seen several discussions about those (I am not going to google them though since I don't want the ATF on my doorstep). ;)
    – JasonR
    Oct 2, 2017 at 18:40
  • 3
    @JasonR There are workarounds that make a firearm effectively (but not legally) behave like an automatic, which are legal.
    – ff524
    Oct 2, 2017 at 21:16

3 Answers 3


A "machinegun" is defined in 26 U.S. Code § 5845(b) as:

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.

Then, referring to this definition, 18 U.S. Code § 922(o) states:

(1) Except as provided in paragraph (2), it shall be unlawful for any person to transfer or possess a machinegun.

(2) This subsection does not apply with respect to— (A) a transfer to or by, or possession by or under the authority of, the United States or any department or agency thereof or a State, or a department, agency, or political subdivision thereof; or

(B) any lawful transfer or lawful possession of a machinegun that was lawfully possessed before the date this subsection takes effect.

So, due to the above, no automatic weapon may be possessed unless it was already lawfully possessed in 1986.

According to the ATF, as of 2016, there were 175,977 pre-1986 machine guns that are legally transferable.

To transfer such a machine gun, ATF form-4 is required.

Examples of requirements made in the form are:


f. Law Enforcement Notification. The transferee must provide a copy of the Form 4 to the chief law enforcement officer (CLEO) who has jurisdiction over the area of the transferee’s address shown in item 2a of the Form 4. In addition, if the transferee is other than an individual, a copy of the Form 5320.23, National Firearms Act (NFA) Responsible Person Questionnaire, completed by each responsible person must be provided to their respective chief law enforcement officer. The chief law enforcement officer is considered to be the Chief of Police; the Sheriff; the Head of the State Police, or a State or local district attorney or prosecutor.



Photographs and Fingerprints. An individual transferee, except if licensed as a manufacturer, importer, or dealer under the GCA, must (1) attach to item 15 of the ATF Form 4, a 2 inch x 2 inch photograph of the frontal view of the transferee taken within 1 year prior to the date of the application and (2) submit two properly completed FBI Forms FD-258(Fingerprint Card with blue lines) with the application. The fingerprints must be clear for accurate classification and taken by someone properly equipped to take them.

The above is federal law. The question also asks about state laws, but this would be a very long answer if it went through ever state and territory of the US.

As an example, the state of Connecticut has a nice SUMMARY OF STATE AND FEDERAL MACHINE GUN LAWS.

The state of Washington has a strict law:

RCW 9.41.220

Unlawful firearms and parts contraband.

All machine guns, short-barreled shotguns, or short-barreled rifles, or any part designed and intended solely and exclusively for use in a machine gun, short-barreled shotgun, or short-barreled rifle, or in converting a weapon into a machine gun, short-barreled shotgun, or short-barreled rifle, illegally held or illegally possessed are hereby declared to be contraband, and it shall be the duty of all peace officers, and/or any officer or member of the armed forces of the United States or the state of Washington, to seize said machine gun, short-barreled shotgun, or short-barreled rifle, or parts thereof, wherever and whenever found.

(but if you already owned the gun in 1994 it's ok to keep; see also RCW 9.41.190)

See also the Wikipedia section Gun laws in the United States by state. Other states with particularly strict machine gun laws are Delaware, Hawaii, Iowa, Minnesota and New York.

  • 6
    You may want to define semi-automatic in your answer. Most non-gun educated individuals probably couldn't distinguish the two types. And to be honest, the rate of fire achievable by a semi-automatic is fast enough that the difference becomes academic when dealing with civilians (as an audience or targets).
    – JasonR
    Oct 2, 2017 at 19:50
  • 18
    @fredsbend presumably the target audience of this question and answer is not purely Americans, and even if it were, wouldn't you want to include the ones who don't know the difference?
    – phoog
    Oct 3, 2017 at 7:17
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    @fredsbend Yes, the American Fetish with guns will have the average person familiar with many aspects of guns, but this site is supposedly meant for a worldwide audience, and given the original askers statement, they are not American, so I think it is valuable information.
    – JasonR
    Oct 3, 2017 at 12:00
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    @lan I would disagree. Bolt action rifles and shotguns, which are probably the primary intended hunting weapons that people are familiar with are far from semi auto. And a revolver's capabilities are generally limited by its capacity compared to something like a police Beretta. Again, my intent is not to fundamentally change the answer. but to give clarity to the non-US and non-gun enthusiasts out there. People see how a gun can be used, but have no idea what its capabilities are, and even though a distinction may exist, how academic it is (the length of these comments sort of show that.)
    – JasonR
    Oct 3, 2017 at 13:34
  • 10
    Although the question is about buying automatic weapons, this answer would probably benefit from a short section about adapting semi-auto weapons for full auto fire. In particular, the fact that the definition of a machine gun includes pulling the trigger makes a legal loophole. One can build a machine to pull the trigger much faster than a human could, thus making a weapon which is legally semi-auto but practically fully-automatic. For a non-US person who is not familiar with the finer points of the legal definitions, this is a way of buying a full auto weapon.
    – Jack B
    Oct 3, 2017 at 13:47

Is it very hard for an American to obtain an automatic weapon?

Yes, it is very hard for an American to obtain a true fully automatic weapon.

It is not, however, difficult for an American to obtain (legal) accessories that allow near-automatic fire rates.

Some quick definitions:

  • Semi-automatic: Fires a single bullet with each press of the trigger
  • Fully automatic: Fires multiple bullets (in bursts or continuously) while the trigger is held down. Also called a "machine gun".

As DavePhD explains nicely in the other answer, true automatic weapons are tightly regulated, but still exist in small numbers (around 175,000 nationally, according to the ATF) where existing pre-1986 guns were grandfathered in. They are rare and expensive and require federal licenses:

The process of registering a NFA item with the ATF is costly, invasive, and time-consuming.... If you wanted to purchase a machine gun today, it would take close to a year....

If you can find a legal, ATF-stamped, pre-1986 machine gun for less than $10,000, you're a miracle worker. A legal NFA sear - the machined part of the trigger group that makes a firearm capable of fully automatic firing - can cost anywhere from $15,000 to $50,000.

You also asked:

there seem to be plenty of American gun enthusiast sites where what look to be automatic weapons are routinely demonstrated

Yep. They are rare and expensive, but also "cool" and popular, so the people who do own them like to show them off. There are places in the country you can go to shoot them on ranges, just for fun.

Semi-automatic rifles are legal, and there are many popular models that look identical to the fully-automatic weapons used by the military, but strictly speaking, they satisfy the "one pull, one bullet" requirement for a semi-auto.

We've recently learned that the Nevada shooter used legal semi-automatic weapons modified with legal "bump-fire" attachments to get a very high rate of fire. These devices are legal because (strictly speaking) you aren't "holding down" the trigger, the gun itself bounces against your finger for every bullet, resulting in near-automatic rates of fire.

Clearly, this is a loophole, and it is uncertain whether these devices (and similar "trigger cranks") will remain legal for long: Gun ‘Bump Stocks’ for Rapid Fire Are Legal. Senators Ask Why..

  • 6
    Calling 175,000 machine guns a "small number" seems very... American to me :-). (Yes, I realize it's small compared to the hundreds of millions of privately owned guns, but still).
    – sleske
    Oct 16, 2017 at 8:42
  • 3
    @sleske: You need to consider it per-capita. There are ~300M people living in the States, so anything not in the millions is effectively tiny.
    – Kevin
    Nov 2, 2017 at 3:15

Fully automatic firearms -- meaning those that fire in bursts with a single pull of the trigger and/or fire as long as the trigger is held down -- are indeed very rare and difficult for a civilian to obtain in the United States.

  • There are only about 180,000 fully-automatic weapons in the US that are legal to buy and own as a civilian. These were all manufactured before 1986. These are very expensive and require months of registration process to transfer.
    • It is possible, but very illegal, to modify many semi-automatic firearms into automatic ones. Fundamentally, automatic firearms are often simpler than semi-auto, because they do not have to stop the bolt or hammer from travelling forward again while the trigger is still pressed. Most semi-auto firearms are intentionally designed to make this conversion difficult to do.
  • However, gaining limited access to a fully-automatic weapon as a civilian is not particularly difficult. These types of access are the main contributors to the enthusiast sites and videos you reference.
    • Fully-automatic weapons can still be manufactured and used by certain businesses, police, and the military. In many cases the businesses that develop, manufacture, and service these guns for those entities are small businesses that may also allow civilians to shoot them as part of testing
    • Many gun ranges and businesses own fully-automatic weapons through one of the above means, and will rent them out for a reasonable price, but only on their own property.
    • Individual citizens who own one of the automatics will often allow others to shoot them at a public or private range, often at organized events where a few (or many) owners and guests get together.
    • There are many methods (with or without additional equipment) to fire a semi-automatic firearm "quickly enough" to be effectively fully automatic, usually at the cost of severely reduced accuracy and handling*. Unfortunately, those disadvantages were not very relevant in the Las Vegas shooting.

Notable Legislation

There are two major pieces of legislation that significantly affect firearms ownership nation-wide (there are more, but these tend to come up a lot and are relevant here for general understanding). I will skip over details for the sake of brevity, but the major impacts to civilians were:

  • the National Firearms Act of 1934 (NFA), which in practice requires a civilian to fill out forms and follow a longer process to register their NFA-item with the ATF (a federal agency), and pay a $200 tax per item. This process generally takes around 6 months, but it varies.
    • Items regulated under the NFA include automatic weapons, suppressors (silencers), rifles and shotguns with short barrels (which includes barrels of now-standard length in the military), etc.
    • Today this act also severely restricts importation of weapons or items in these categories, making them more expensive in addition to the tax.
  • The Gun Control Act of 1968, amended significantly in 1986 to ban the possession of automatic weapons manufactured after that date.

In other words, to get a fully automatic weapon, you need to transfer it according to the NFA rules, registration, and tax, and it must have been manufactured and civilian-owned prior to 1986. This is the fundamental truth behind someone stating that "fully automatic guns are very rare and hard to get" in the US.

Note that because either the gun's receiver (the block that the barrel, stock, and trigger all connect to), or the sear (the part that holds back the hammer until the trigger is pulled) are the regulated parts, one can often build "a whole different gun" around a registered fully-automatic receiver.

"Bump Stocks" etc.

There are lots of good resources explaining bump stocks, but fundamentally they have been legal up to this point (since their fairly recent invention) in part because they do a poor job* of turning a semi-automatic weapon into an automatic one. Up to this point there has not been a legal line drawn between "attempting to produce an automatic weapon" and simply modifying a firearm or its trigger for better performance, such as a lighter, shorter trigger pull for competition shooting (which also facilitates increased fire rates).

"Trigger crank" devices are similar in that they come with major disadvantages, but may be more effective or their "loophole" intent more clear. Unfortunately the Las Vegas shooting is an rare (or even unprecendented) instance where these "seemingly scary" but generally highly impractical devices may actually have contributed to the loss of life.

Note: *It is difficult to reference a particular source for my claims that "simulated full auto" devices and techniques fundamentally reduce accuracy and handling, because up until very recently, no one had actually used them in a "real world" matter. However, fundamentally each method (bump stock, crank, belt loop, etc) tends to change the way the gun is handled in some significant way, such that it deviates from how the gun was intended to be used or standard marksmanship practice. In the crank and belt loop cases this is obvious. In the bump stock case, consider that the gun must actually be held loosely and pulled away from the shoulder while firing to simulate automatic fire, which is precisely the opposite of proper shooting technique for multiple accurate shots. As evidence, consider the angled and vertical foregrips typically seen on modern military rifles. These exist specifically to "pull back" on the gun, not forward.*

State Law

In general, the second amendment to the US constitution can prevent states from imposing major restrictions on firearms ownership, as happened with the removal of Washington D.C.'s complete handgun ban, but the topic of what firearms the 2nd amendment protects, for whom, and to what degree, is an ongoing debate in the US. States and counties therefore tend to implement gun control as strictly as their constituencies allow, and challenges to constitutionality may or may not affect the implementation of such laws.

The waters are therefore even murkier with state firearms law when fringe topics like automatic weapons are involved. Some states require registration with county law enforcement (beyond that which is already effectively required by the NFA), but county law enforcement can potentially refuse to register an automatic firearm for any reason. Certain states allow this "may issue" behavior (thus effectively making ownership impossible in a given county), while others either don't have such a requirement or have objective rules for registration instead of discretionary ones.

This is only one of undoubtedly several different types of additional restrictions that will vary from state to state, and is based on some research about states in the southeast specifically. The short version is that yes, laws do vary from state to state, but because automatic firearms are very rare, the laws about them are neither in the public eye nor the broader gun-owning public's eye very often, so the law in a given locale can be very unclear.

  • 2
    You will get some leeway, but you will need to provide references as questions without them do not fare well here. Your answer looks good enough to do well if all its claims are properly referenced.
    – matt_black
    Oct 13, 2017 at 18:19
  • nytimes.com/interactive/2017/10/02/us/vegas-guns.html shows bumpstocks get about halfway between auto and semi auto, I dont have a good link for the sacrifice in accuracy
    – daniel
    Oct 13, 2017 at 20:09
  • 1
    @daniel It may be overly simplistic to look at the stocks in terms of what kind of fire rate they can manage. I can imagine a bump stock actually exceeding the typical full-auto rate of fire for certain guns, depending on how the "real" full auto activates. At any rate, I added information about accuracy. While I do not have a good source, hopefully I explained that bump stocks require "poor" gun handling techniques to work, so a negative effect on accuracy can be reasonably assumed. Again, and unfortunately, reduced accuracy likely had minimal effect in the Vegas shooting.
    – gkimsey
    Oct 15, 2017 at 18:33
  • I just watched this and no longer care about bump stocks, usa should ban microcontrollers youtu.be/RxBa5bQfTGc
    – daniel
    Oct 15, 2017 at 19:11
  • You might mention that one reason bump stocks aren't covered by those laws is they were invented after those laws were written. Oct 18, 2017 at 20:10

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