The Ultimate Firearms Destination for the Gun Lifestyle

The 80 Percent Lower, the Ghost Gun, and the ATF

The trouble with technology is that it grows faster than it can be regulated. At least this is something that might be considered when the time-labored process of legislation is met with the growth rate of homemade guns. As 3D printed gun files, incomplete components, and the internet have jumped centuries in providing a way for private citizens to produce their own firearm in their own home, we're no longer looking at simply hand-crafting a flintlock pistol, but actually completing a functioning semi-automatic firearm all within the four walls of a condo. On the one hand, the old terms of the relationship between the agency colloquially referred to as the ATF, are no longer relevant, and on the other hand, new terms such as “Ghost Gun,” and concepts like an 80 percent lower now populate the news, feeds, and Search Engine results of people around the world.

On May 21st, 2021, the Bureau of Alcohol, Tobacco, Firearms, and Explosives, or ATF for short, published a new proposed rulemaking that would redefine what the government defines as a firearm. This is presented as an amendment to the currently understood definitions of a complete firearm, a suppressor (or silencer), and a gunsmith. Citizens have until the 18th of August, 2021 to comment on the new proposal.

80 percent arms cover

In order to understand this proposal, we must look at its consequences, both within the group of people politically segregated as “gun owners” and in relationship to the government as a whole.

Situationally Dependent History

The 80 percent lower was not solely an invention, so to speak, of technical innovation alone, but one surrounded by legal constraints. With a foundation rooted in the technological advancement of firearms like the AR-15, and polymer-handled, striker-fired handguns, they also came about in relation to the Gun Control Act of 1968 (GCA) and the National Firearms Act of 1934 (NFA).

Before modern manufacturing and the concept of interchangeable parts, popularized first in American weapons by Eli Whitney in the early 1800s, agrarian cultures relied on either a specialized gunsmith within their community or the burgeoning industrial giants such as England to provide firearms. Over time, it became easier and easier for the average citizen to build their own firearm as industrial standards improved, and distribution paths expanded across land, sea, and air.

80 percent lower 80 percent arms complete

This, however, was not limited to building a so-called proto ghost gun, but modification (see personalization) also naturally occurred during the early days of American frontier living. During the fur trade, the North West Gun would become the most popular due to its lighter weight and shorter barrel, and numerous examples of modified guns can be found in museums.

The ability to replace interchangeable parts to repair a firearm evolved into the modular firearms of today, where components, as well as attachments, could be swapped out at will by the end-user. This challenged the notion of which part or components were vital to the operation of a specific firearm. Thus we arrived at the term frame or receiver as: “That part of a firearm which provides housing for the hammer, bolt or breechblock, and firing mechanism, and which is usually threaded at its forward portion to receive the barrel” in the Federal Firearms Act of 1938.

The frame or receiver is where the serial number can be found, and is the primary component regulated by the ATF. Non-serialized components can be purchased without a background check, as they themselves are incapable of being used as a firearm.

polymer80 lower

For many guns, such as the AR-15, this was interpreted as the lower reciever, likely due to the adoption of the M16 and later, M4, and its subdivisions such as the MK18 by the United States Military. This deviation from the above definition, as the lower receiver of an AR-15 holds the hammer but not the bolt, led to the development of the 80 percent lower which some call a ghost gun. These items required the purchaser to cut, mill, or drill an otherwise semi-shaped piece of material in order to adapt it into a useable lower for an AR-15, and later, handguns.

The technology for creating these parts of varying levels of reliability is readily available to citizens due to the ever-increasing affordability of 3D printers, hobbyist mills, and interchangeable components. In addition to this, firearms such as the SIG P320 FCU rely on the interpretation and acceptance by the ATF that the fire-control group represents the serialized component of the firearm in order to expand modularity. A P320 FCU can not only be swapped from a smaller grip module prioritizing concealability to a larger one more appropriate for fast-paced competitive shooting, but it can also be placed into a Flux Defense MP17 or B&T USW frame, drastically altering the firearm as a whole.

80 Percent Lower

The concept of an 80 percent lower has a linguistic, legal, and metaphysical aspect to it. The language around an 80% lower recognizes that it could potentially be made to operate as a functional firearms component with additional fabrication. An 80 percent lower is sometimes referred to as a receiver blank.

80 percent lower in a pile

Legally, since it is not sold as a complete firearm, and merely has the potential of being fabricated into one, an 80 percent lower does not fall under the regulations surrounding the sale and transfer of firearms (results vary from state to state). They are, however, bound by other conditions, such as a private citizen may not fabricate a firearm for the purpose of selling it, and giving a privately made firearm to person known to be prohibited from possessing a firearm is can be considered a crime.

So the metaphysical (base concept: what is reality?) question asks two things: is the designation of 80% arbitrary? And if regulated, at what point does an object become a potential firearm? Since most AR-15 lower receivers are fabricated out of a single piece of aluminum, and most polymer handled pistols include a fire control group nested into a one-piece polymer lower, if interpreted merely on potential, than a person with a lathe and a block of aluminum, or someone with a 3d printer could technically be considered to be owning components needed to build a firearm.

The ATF's New Proposal

The new proposal by the ATF openly states that it seeks to provide new regulatory definitions of “firearm frame or receiver” and “frame or receiver.” In addition to this, the definition of a “firearm,” a “gunsmith,” are to be amended. New definitions include “complete weapon,” “complete muffler or silencer device,” “privately made firearm,” and “readily.”

In the background paragraphs regarding how the ATF has identified which component of a split receiver model would be considered the serialized part, they recognized that firearms such as the 1911, AR-15/M-16, and FAL parts determined to be the receiver did not technically fall under the guidelines they provided at the time of their classification. Their implicit reasoning was that they viewed these items as primarily manufactured for military use.

The term “Firearm” includes the following: “(A) any weapon (including a starter gun) which will or is designed to or may readily be converted to expel a projectile by the action of an explosive.” It is proposed that the following be included: “[t]he term shall include a weapon parts kit that is designed to or may readily be assembled, completed, converted, or restored to expel a projectile by the action of an explosive.”

The proposal presents four supplements to the definition of a “frame or receiver” explicitly stating to include “any housing or holding structure for a hammer, bolt, bolt carrier, breechblock, cylinder, trigger mechanism, firing pin, striker, or slide rails.” It first singles out four types of examples: revolvers, bolt action rifles (likely to include bolt action shotguns however rare), break, pump, and lever-action rifles and shotguns, and finally: semi-automatic firearms and machineguns as a fourth category.

80 percent lower
  • The first supplement identifies only the exposed tube to be the serialized component of a Silencer.
  • The second supplement regards modular and split frames or recievers acknowledges that the majority of firearms use this format of construction. Under this proposal, the ATF will have the responsibility of identifying the serialized reciever on a split design.
  • The third supplement, however, would include “in the case of a frame or receiver that is partially complete, disassembled, or inoperable, a frame or receiver that has reached a stage in manufacture where it may readily be completed, assembled, converted, or restored to a functional state” to the definition of a frame or reciever.
  • The fourth supplement reinforces what factors the ATF uses to determine if a firearm, frame, or receiver has been destroyed.

The provided definition for readily is: “a process that is fairly or reasonably efficient, quick, and easy, but not necessarily the most efficient, speedy, or easy process.”


A complete firearm as defined by the proposal is: “a firearm other than a firearm muffler or firearm silencer that contains all component parts necessary to function as designed whether or not assembled or operable.”

It defines a Privately Made Firearm as: “[a] firearm, including a frame or receiver, assembled or otherwise produced by a person other than a licensed manufacturer, and without a serial number or other identifying markings placed by a licensed manufacturer at the time the firearm was produced.”

Regarding the Term: Ghost Gun

The term ghost gun has begun circulating in primarily political spheres since at least 2014. A phrase referring to privately made firearms, implicitly correlating their lack of serial number with either criminal activity or dangerous possession. The act of fabricating an 80 percent lower into a privately made firearm has been tacitly referred to as building a ghost gun.

Privately Made Firearms, Then and Now

The act of building one's own firearm whether through an 80 percent lower, or by other means, challenges the capabilities of regulation and identifies the locus of power within a country. A representative government may appoint agents to enforce specific laws, but unelected officials are not supposed to be able to write legislation.

An 80 percent lower is only called such because that is the amount of work required for the possessor of the blank to modify it into a complete firearm. Further, the process of 3D Printing firearms parts can effectively make such regulation obsolete, except as a hindrance to otherwise law-abiding citizens.

3d printers
3D printers churning away. Iain may or may not be drinking beer. (He is.)

The proposed definitions struggle under these two problems. On the one hand, the idea of an agency such as the ATF, with its turbulent past, being given authority to redefine physical objects as inside or outside of their enforcement raises concern. On the other, the proposed regulations either turn otherwise law-abiding citizens into criminals, or further burdens them with bureaucratic oversight, the second supplement aside.

The creation of new definitions should be seen with suspicion, especially when paired with its correlation with enforcement. Having the ATF define what constitutes a privately made firearm could be considered to a police agency also having the authority to write and tweak the laws they enforce without having to go through a legislative body.

This, placed against the backdrop of the right to bear arms culminates in a series of historically defining moments. As much as the ATF Pistol Brace Ban gathers more attention since the proposal of these new definitions, States such as Nevada and Hawaii have already enacted retroactive prohibitions on privately made firearms, with their components in suspect, without grandfather clauses.

Commenting on the New Proposed Definitions

The new proposed definitions and supplements present more than a few problems. As much of the strife between Law Abiding Citizens and the ATF meet at the often vague if not elusive definitions provided, so it follows that the only interpretation that is enforced is that of the Agency, always at the cost of the populous. If the Agency were to interpret a series of components as merely being capable of being assembled into a firearm, as if it were a fully functioning illegally possessed gun, no matter how convoluted, the burden on the individual would exceed acceptability. Further, the notion of considering the possession of a privately made firearm as a crime inverts the principle of “Innocent until proven guilty.” Instead of comparing this to other, more currently palatable infringements on American's Human rights, the newly proposed definitions should be rejected.

Finally, in a sense of humor, it seems the ATF weeks to punish people who know their way around a workshop, as it subjectively infers that a piece of metal might be regulated as a firearm receiver simply because the purchaser is handy.

The comment period ends soon on 18 August, 2021. It is unclear to what exact extent the comment period makes an impact because we are dealing with the subjectivity of humankind, but the track record on larger proposals such as the proposed M855 ban's failure to establish shows that silence is the worse of two options. Here's how to submit comments:

  • Federal eRulemaking Portal: ATF recommends that you submit your comments to ATF via the Federal eRulemaking portal at and follow the instructions. Comments will be posted within a few days of being submitted. However, if large volumes of comments are being processed simultaneously, your comment may not be viewable for up to several weeks. Please keep the comment tracking number that is provided after you have successfully uploaded your comment.
  • Mail: Send written comments to:

Office of Regulatory Affairs, Enforcement Programs and Services, Bureau of Alcohol, Tobacco, Firearms, and Explosives, 99 New York Ave. NE, Mail Stop 6N518, Washington DC 20226; ATTN: ATF 2020R-10.

  • Written comments must appear in minimum 12-point font size (.17 inches), include the commenter’s first and last name and full mailing address, be signed, and may be of any length.
  • Facsimile: Submit comments by facsimile transmission to (202) 648-9741. Faxed comments must:
    • 1. Be legible and appear in minimum 12-point font size (.17 inches);
    • 2. Be 8 ½” x 11” paper;
    • 3. Be signed and contain the commenter’s complete first and last name and full mailing address; and
    • 4. Be no more than five pages long.

It is advised that you read the original document published by the ATF before submitting your comments, so that it will be maximally effective.

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8 responses to “The 80 Percent Lower, the Ghost Gun, and the ATF”

  1. Ron says:

    This comment will probably be deleted by the moderator(s), but such egregious abuse to the rules of grammar and the flagrant misspellings demand comment.

    For crying out loud, use spell check or preferably, get someone to proof your articles.

    A quick review of the article follows:

    “redifind” – “redefined”

    “politcally” – “politically”

    “sequestered” – Actually means “isolated and hidden away”, like a jury being sequestered.
    Gun owners are “politically separated” or “politically segregated”.

    “it’s” (2 occurrences)- The possessive form of “it” becomes “its”. “It’s” is a contraction of “it is”.

    “reciever” (14 incorrect occurrences) – “receiver” – Note: Used correctly 5 other times, obviously copied from other text.

    “hobbiest” – “hobbyist “

    “concealeability” – “concealability”

    “…than a person…” – “…then a person”… Used as an adverb, not as a conjunction.

    “explicitely” – “explicitly“

    “catagory” – “category”

    “implicitely” – “implicitly”

    “governement” – “government”

    “…its turbulent… “- The possessive form of “it” becomes “its”. “It’s” is a contraction of “it is”.

    redifine – “redefine”

    …seen with suspect… – …seen with suspicion…

    “…especially when paired with its correlated with enforcement…” – Awkward sentence, maybe
    “…especially when paired with enforcement…”
    “…especially when correlated with enforcement…”
    “…especially when paired with its correlation with enforcement…”

    “…Having the ATF define what constitues a privately made firearm could be considered to a police agency also having the authority…” – “…Having the ATF define what constitues a privately made firearm could be compared to a police agency also having the authority…”

    “constitues “ – constitutes

    “tweek” – “tweak”

    “…cost of the populous…” – “…cost to the populace …”.
    “Populous”, meaning “having many inhabitants”, is always an adjective.
    “Populace” is a noun referring to a population or the general public.

    “…American’s Human…” – “…Americans’ Human…”. American needs to be the plural form “Americans” and the possessive of the plural has the apostrophe AFTER the “s”.

    “…the ATF weeks…” – “…the ATF seeks…”.

    • Geoff says:

      Don’t feel bad. I get riled up over people confusing “loose” and “lose”.
      “their” – possessive
      “there” – a location
      “they’re” – a contraction of “they are”
      “were” – past tense of “are”
      “we’re” – contraction of “we are”
      “where” – a location
      “lead” and “led”
      There are more, but I can’t think of them offhand.

      • Haz says:

        My grammar OCD makes my eye twitch when people make such basic mistakes. It distracts from the author’s message.

        • David says:

          I am glad I am capable of reading and still understanding. Regardless of grammar or spelling I find those who criticize grammar as some sort of philosophical retort, to be the most ignorant among us. These individuals fail to recognize even the the basic arguments being made let alone intellectually arguing their points.

    • Mike says:

      I’m glad I was not the only person who noticed all the grammar and writing errors. C’mon Recoil. Do better.

      • Garrett Hines says:

        I sincerely hope the author shoots better then he writes. I agree. A person looking to belittle gun owners would read this article and point out all the misspellings and bad grammar and use that to infer we’re a bunch of illiterate idiots. Please have someone proof read next time.

  2. Joe Martin says:

    The very fact that BATF can write its own laws and then apply them using “Administrative Law” is beyond disgusting and completely illegal. Administrative Law is unconstitutional as Congress is the only entity authorized by the Constitution to write law, but all Federal agencies us the process of Administrative Law to circumvent Congress to make regulations with the effect of law. If you believe your comments will have any bearing on BATF’s actions whatsoever, you are a special kind of stupid. Administrative Law requires new regulations to be posted in the Federal Register and a comment period applies, but there is nothing in the process that requires BATF or any other Federal agency to pay attention to the comments and there are no penalties for simply ignoring them.

    • StLPro2A says:

      “…..and there are no penalties for simply ignoring them.” Therein lies the age old problem. Government critters face no consequences of their tyrannical actions. They do not fear We The Little Peeps. They see our money, rights, freedoms, and liberties as theirs to skim, scam, squander and with which to buy votes to further solidify their power, wealth, and control agendas. They have not been shown and convinced that We The Little Peeps will do anything to protect our Constitutional rights, freedoms, and liberties…..except pay the likes of GOA, NRA, FPC, SAF to play by the enemies’ rules and thus lose by the enemies’ rules…..ala court actions. The 2A IS BIG BUSINESS for both sides of the issue, with We The Little Peeps caught in the middle doing nothing, but grousing and rattling toy sabers. Our Founding Fathers would have already been finished shooting a second time. They are ashamed of what we have relinquished, with nary a shot, of what they put their all on the line to create and pass down to us. Obviously we don;t feel we have enough invested to do anything but grouse and write meaningless comments to tyrannical government tyrants to ignore….and then grouse some more.

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