80 Percent Lower Ruling: What It Covers and Who It Protects
A Texas court voided the ATF’s 2022 unfinished-frame rule as vague, but only for Defense Distributed, the Second Amendment Foundation and its members.
Last updated: September 2, 2026 · Originally published September 1, 2026
The history, and why the Biden administration went after 80% kits
Federal law has said since the Gun Control Act of 1968 that a “firearm” includes both a working gun and “the frame or receiver of any such weapon.” For decades after that, ATF treated a raw or mostly unfinished block as something short of a regulated frame or receiver. Industry called those parts “80% lowers” or “80% frames.” The number was marketing, not a statute. ATF itself has long said it does not classify items by a percentage. In practice, a blank with an unmachined fire-control cavity was often sold without a serial number, without an FFL transfer, and without a Form 4473.
That market grew with polymer pistol frames, AR-pattern rifle lowers, jigs, CNC “ghost gunner” machines, and later 3D printing. The finished product is a privately made firearm, or PMF: a gun built by someone who is not a licensed manufacturer and that does not carry a factory serial number. Building a non-NFA firearm for personal use has never, by itself, been a federal crime for a person who is not prohibited from possessing guns.
The Biden Justice Department and ATF framed the problem as “ghost guns.” Their argument was that kits and unfinished frames were reaching prohibited persons, showing up at crime scenes, and defeating tracing because there was no serial number and no dealer record. Courts had also started poking holes in ATF’s old definition of “frame or receiver,” which was written for older one-piece designs. Officials warned that if that old definition were applied rigidly to modern split receivers and striker-fired pistols, large categories of common guns might not have a regulated “frame” at all.
In May 2021 ATF proposed a rewrite. In April 2022 it published Final Rule 2021R-05F, Definition of “Frame or Receiver” and Identification of Firearms. The rule took effect August 24, 2022. Two changes mattered most for 80% products:
- A “frame or receiver” would include a partially complete, disassembled, or nonfunctional frame or receiver, including a parts kit, that “is designed to or may readily be completed, assembled, restored, or otherwise converted to function as a frame or receiver.”
- A “firearm” would include weapon parts kits designed to or readily convertible into a working gun.
“Readily” was judged by a non-exclusive list of factors: time, ease, expertise, equipment, availability, expense, scope, and feasibility. The rule also required FFLs who take privately made firearms into inventory to serialize them, and it updated marking and recordkeeping. Raw material including an unformed block of metal was still excluded. Almost everything between that raw block and a finished receiver was pulled into the regulated category if ATF decided it was “clearly identifiable” and “readily” completable, especially if sold with a jig, template, or tools.
Litigation started immediately. Judge O’Connor first vacated the rule on statutory and Administrative Procedure Act grounds. The Fifth Circuit largely agreed. In March 2025 the Supreme Court reversed in Bondi v. VanDerStok (the same case under earlier names), 7–2. Justice Gorsuch wrote that the Gun Control Act is not facially inconsistent with ATF regulating some weapon parts kits and unfinished frames. The Court did not decide whether the rule violated the Second Amendment or was unconstitutionally vague. Those questions came back to Fort Worth. After remand, the remaining plaintiffs were Defense Distributed and the Second Amendment Foundation. The case is now captioned Defense Distributed v. Blanche.
What an 80% receiver is, and why people finish their own firearms
An 80% receiver or 80% frame is an unfinished housing that has 20% more work needed to make it into a functioning firearm. It looks like a gun part. It is not yet the part that federal law treats as the firearm until the last critical machining is done, typically the fire-control cavity on an AR lower, or the corresponding cuts on a pistol frame. The buyer still has to drill, mill, or otherwise complete that area, then install a trigger group, barrel, slide or upper, and the rest of the parts.
Why build your own firearm:
- Personal manufacture. Home gunsmithing is older than the Republic. Early Americans made and repaired their own arms. That history is the backbone of O’Connor’s Second Amendment analysis.
- A legal firearm without a factory serial number. Federal law has not required an unlicensed person to serialize a gun made for personal use. That is the feature critics call a “ghost gun” and builders call a privately made firearm.
- Cost and availability. A kit plus parts can be cheaper than a complete factory gun, or available when a particular configuration is hard to find.
- Customization. Builders choose triggers, furniture, caliber, and cosmetics sort of like the way people build PCs.
- The hobby itself. Completing a lower is machining fitting and assembly.
None of that made the builder a licensed manufacturer, so long as the person was making a gun for personal use and not “engaging in the business” of manufacturing or dealing. Machine guns, short-barreled rifles, and other NFA items were always a different statute. Selling the finished gun, or making guns for others as a business, was always a different statute too.
Basically to break it down in a simple terms as possible: no law, prohibits, and individual who is not prohibited from owning a firearm from manufacturing their own firearm for personal use. Basically you could build a firearm for yourself, but not build firearms for sale unless you had a manufacturers license.
The 2022 rule did not ban home building in so many words. It tried to regulate the starting point. If the unfinished part or kit was already a “firearm,” then selling it required a license, a serial number, a background check, and dealer records. That is what collapsed the commercial 80% market for companies that did not want to become FFLs.
What Judge O’Connor ruled, in plain English
O’Connor granted the plaintiffs summary judgment on two constitutional claims and granted the government summary judgment on the leftover APA claims. He did not pretend the Supreme Court had not already answered the statutory question. He answered the questions the Supreme Court left open.
1. The rule is too vague. The Fifth Amendment requires fair notice before the government can treat conduct as a crime. The judge said the 2022 rule fails that test. The key phrase is whether a hunk of metal or plastic “may readily be completed, assembled, restored, or otherwise converted to function as a frame or receiver.” That call is made with a non-exclusive eight-factor test. The rule also says a forging, casting, printing, or similar article becomes a frame or receiver once it is “clearly identifiable as an unfinished component part of a weapon,” while a raw block or liquid polymer is not. O’Connor’s point was simple: nobody can tell where the line is. Between a brick of aluminum and a finished lower, the rule never says the moment the object becomes a felony to sell without a license. That decision, he wrote, “is left to the subjective determination of the ATF and does not provide fair notice to the reader about when a component becomes subject to enforcement.”
2. The rule conflicts with the Second Amendment as the Supreme Court now reads it. After New York State Rifle & Pistol Association v. Bruen, a gun regulation that burdens protected conduct has to fit the nation’s historical tradition of firearm regulation. O’Connor found personal manufacture and gunsmithing in that tradition. He wrote that self-manufacture of firearms in America “was common and indeed foundational to establishing our Nation,” that regulations on self-built arms are not longstanding, and that there were no restrictions on making arms for personal use in the seventeenth, eighteenth, or nineteenth centuries. In his view the 2022 rule does not merely lack a historical analogue. It “contradicts the actual historical tradition of personal gunsmithing” by choking off access to the component parts people use to build guns at home.
3. The remedy is a declaration plus a permanent injunction but not a nationwide deletion of the entire 2022 rule. The court declared 27 C.F.R. § 478.11 and § 478.12(c) unconstitutional under the Second Amendment and void for vagueness, and said those provisions cannot be enforced against Defense Distributed, the Second Amendment Foundation, or SAF’s current or future members. It then enjoined enforcement of those two provisions against those parties with respect to specific Defense Distributed products: M1911 80% frames and the G80 build kit, unfinished receiver, and grip module.
“The court got it right. ATF did not respect Bruen. There is no history or tradition of regulating privately made firearms in this country.”
Cody Wilson, founder, Defense Distributed
Who is covered, and who is not
Covered, according to the order:
- Defense Distributed.
- The Second Amendment Foundation.
- Current and future SAF members.
- The listed Defense Distributed products: M1911 80% frames; G80 build kit; G80 unfinished receiver; G80 grip module.
SAF has said the court declared the rule unconstitutional as applied to all SAF members and enjoined enforcement against them as to the kits in the case. That is associational standing doing a lot of work: one membership organization, a large and open-ended class of members, and a handful of named products.
Not automatically covered:
- People who are not SAF members.
- Other unfinished-frame companies and other product lines, unless they separately obtain relief.
- Every 80% lower on the internet. Polymer80-style Glock-pattern frames, generic AR blanks from other sellers, and random “80% kit” listings are not named in the injunction.
- State and local prosecutors enforcing state precursor-part laws.
- Conduct the 2022 rule never had to reach: selling a completed firearm, manufacturing for sale as a business, transferring a gun to a prohibited person, or making an NFA weapon without approval.
| Covered by the injunction | Not covered |
|---|---|
| Defense Distributed and SAF as organizations | The general public |
| SAF’s current and future members | Non-members buying the same parts |
| M1911 80% Frames | Any other maker’s unfinished blank |
| G80 Build Kit, Unfinished Receiver, Grip Module | Polymer pistol frame kits from other sellers |
| 27 C.F.R. § 478.11 and § 478.12(c) | The rest of the 2022 rule |
What changed for builders as of September 2, 2026
Three things are true this morning:
- SAF members have real protection on four specific products. The injunction names current and future members. Membership is open to the public and costs less than a case of 9mm.
- Everyone else is where they were on August 17. The 2022 rule is still printed in the Code of Federal Regulations and still enforceable against people who were not parties.
- The reasoning is now on the record. A published federal opinion holding these provisions vague and inconsistent with the Second Amendment is ammunition for the next plaintiff, and for Congress.
The Justice Department has not said whether it will appeal to the Fifth Circuit. That silence is itself worth watching, and it follows the April package of ATF rule rollbacks and the department’s own reform announcements.
What did not change
Bondi v. VanDerStok is still good law on the threshold question. The Supreme Court confirmed in 2025 that Congress delegated authority to the ATF to define “frame or receiver” under the Gun Control Act. This ruling does not disturb that. It says the agency drew the line in a way ordinary people cannot follow.
Also untouched: every rule about who may possess a firearm at all. A prohibited person cannot build one. Interstate transfer rules still apply to a finished receiver. None of that moved.
If you already own an 80 percent lower
Plenty of readers have a blank sitting in a drawer, bought before 2022 and never finished. Nothing about the August decision makes that blank riskier than it was last month, and nothing about it makes finishing the blank safer either.
The practical questions are the same three they have always been. Does your state require a serial on a self-made firearm, and if so, within what window? Was the blank purchased before the 2022 rule took effect, and can you show that? And is the finished configuration — barrel length, overall length, stock or brace — legal where you live?
Answer those in that order. The federal question is the one everyone argues about online and the one least likely to reach you. The state question is the one that puts people in front of a judge.
If the answers come back clean and you decide to finish it, the receiver is only the beginning of the parts list. That is a separate project with its own set of specifications, and the fit between your finished lower and everything bolted to it is where a home build succeeds or rattles.
State law is the sharper edge for 80 percent lower builds
Federal status is only half the question, and for many readers it is the easier half. A number of states require a serial number on any self-made firearm regardless of how federal law classifies the blank, and a few restrict the blanks themselves. A build that is lawful under federal law can still be a felony in your state.
Check your state statute before ordering, not after. This is the single most common way otherwise careful builders get into trouble, and no federal court decision fixes it for you.
What to watch next
Appeal. The Department of Justice has continued to defend the 2022 rule in court even after the change in administrations. An appeal to the Fifth Circuit is the expected next filing. Either side can later ask the Supreme Court to take the constitutional questions the 2025 decision left on the table.
The real width of “SAF members.” The order reaches current and future members and named Defense Distributed products. Expect fights over who counts, which products count, and whether sellers who are not Defense Distributed can stand in the same shadow.
Copycat suits. Other companies and other organizations will try to turn this opinion into broader relief. Some will win party-specific injunctions. Some will lose. A single district-court win is not a national regulation.
Congress and ATF. If the Fifth Circuit or the Supreme Court leaves a hole, Congress can write an actual statute about unfinished frames. ATF can also try to rewrite the definitions so they are less vague and more tightly tied to history. Either path would matter more than another press release about “ghost guns.”
State legislatures and state courts. The states that already ban precursor parts are not waiting for Fort Worth. Some are adding 3D-printer and CNC restrictions on top. Those statutes will be challenged under Bruen on their own records.
Final Thoughts
Until a higher court says otherwise, the honest summary is this: Judge O’Connor held that two ATF definitions cannot be enforced against Defense Distributed, SAF, and SAF members as to specific unfinished Defense Distributed products, because those definitions are unconstitutionally vague and burden a historically unprotected-from-regulation practice of personal gunsmithing. Everyone else is still living under the Gun Control Act, under whatever remains of the 2022 rule, and under the state law where they sleep.
Remember this is an explanation of a court order from a non lawyer. It is not legal advice. If a kit, a membership, or a homemade firearm is on the line, read the actual injunction and talk to a lawyer who does this work in your state.
Frequently asked questions
Are 80 percent lowers legal again nationwide?
No. The August 18 ruling is an as-applied decision. It blocks enforcement of two regulatory provisions against Defense Distributed, the Second Amendment Foundation, and SAF members, and only for four named Defense Distributed products. The 2022 frame-or-receiver rule remains in the Code of Federal Regulations for everyone else.
Does joining SAF make my home build legal?
Membership brings you inside the injunction, but the injunction covers specific Defense Distributed products, not every blank on the market. It also does nothing about state law in your jurisdiction. Membership supports the litigation and gives you standing under this order; it is not a blanket permission slip.
Do I have to serialize a receiver I finish myself?
Federal law has not required a serial on a firearm made for personal use, and this ruling does not change that. Several states do require one, sometimes within days of completion. Your state statute controls, and the penalty for guessing wrong is a felony.
Can I sell a rifle I built from an 80 percent lower?
Building for personal use is treated differently from building to sell. A firearm made with the intent to sell can trigger manufacturing and marking requirements. If you are thinking about selling a home build, talk to a lawyer in your state first.
What happens if the DOJ appeals?
The case goes to the Fifth Circuit, and the injunction stays in force unless a court stays it. An appellate ruling would carry weight across Texas, Louisiana, and Mississippi, and would shape how other circuits read the vagueness question.
The bottom line
A federal judge just wrote that Americans have made their own arms since before there was a country to regulate them, and that the agency policing that tradition could not explain its own rule clearly enough to be followed. That reasoning will outlive this injunction.
What it will not do is machine your fire control pocket. Until the next ruling, the safest build is still the one where you read your state statute before you clamp the jig.
Sources and method: This report is based on Judge Reed O’Connor’s August 18, 2026 opinion and final judgment in the Defense Distributed and SAF litigation, the text of 27 C.F.R. § 478.11 and § 478.12(c) as published in the eCFR, the Supreme Court’s 2025 decision in Bondi v. VanDerStok, and public statements from Defense Distributed. Updated September 2, 2026.
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