80% Firearm Kits

Educational information, not legal advice. Gun laws change often and vary by state, county and city. Check current law where you are and talk to a firearms attorney before acting. Full disclaimer

Last reviewed November 1, 2026

80% Firearm Kits: Where It Stands in 2026

Americans have built their own firearms since before the founding, and federal law has never required a license for an unlicensed person to make a gun for personal use where state law allows it. What changed is how the law treats unfinished frames, receivers and parts kits. ATF’s “Frame or Receiver” rule (Final Rule 2021R-05F), effective August 24, 2022, treats a frame or receiver that “may readily be completed,” and a parts kit that can readily be assembled into a working gun, as a “firearm” under the Gun Control Act. Covered products must be sold through licensed dealers with serial numbers, a Form 4473 and a background check.

Warning: maps are habit forming. Next stop, 2A Maps

No State Restriction (34): Alabama, Alaska, Arizona, Arkansas, Florida, Georgia, Idaho, Indiana, Iowa, Kansas, Kentucky, Louisiana, Maine, Michigan, Minnesota, Mississippi, Missouri, Montana, Nebraska, New Hampshire, New Mexico, North Carolina, North Dakota, Ohio, Oklahoma, Pennsylvania, South Carolina, South Dakota, Tennessee, Texas, Utah, West Virginia, Wisconsin, Wyoming

Serial Number or Partial Rules (3): Connecticut, Maryland, Massachusetts

Ban on Unserialized Guns or Kits (15): California, Colorado, Delaware, District of Columbia, Hawaii, Illinois, Nevada, New Jersey, New York, Oregon, Puerto Rico, Rhode Island, Vermont, Virginia, Washington

How this map is researched, from statute to state note: How We Research.

On March 26, 2025, the Supreme Court in Bondi v. VanDerStok (7-2) rejected a facial challenge to the rule, holding that the Gun Control Act’s definition of “firearm” can reach some kits and unfinished frames. The Court did not say every 80% product is a firearm; the answer depends on how complete the product is and what comes with it. Justices Thomas and Alito dissented.

The fight then moved to the Second Amendment. In August 2026, Chief Judge Reed O’Connor of the Northern District of Texas held parts of the rule (27 C.F.R. 478.11 and 478.12(c)) unconstitutional under the Second Amendment and as unconstitutionally vague under the Fifth Amendment, finding no historical tradition supporting it and pointing to the long American tradition of personal gunsmithing. That relief is limited to the parties, including Second Amendment Foundation members, and to the specific products in the case. It is not a nationwide ruling, and appeal status should be checked.

Key Facts

August 24, 2022: ATF Frame or Receiver rule takes effect (27 C.F.R. 478.11, 478.12).
March 26, 2025: Bondi v. VanDerStok, 7-2, upholds the rule against a facial statutory challenge.
August 2026: N.D. Texas holds parts of the rule unconstitutional; party-specific relief only.
State laws: 15 states plus D.C. regulated unserialized or unfinished frames and receivers in some form as of August 2025 (California, Colorado, Connecticut, Delaware, Hawaii, Illinois, Maryland, Massachusetts, Nevada, New Jersey, New York, Oregon, Rhode Island, Vermont, Washington), per the Duke Center for Firearms Law.
January 2026: Maine’s serial-number law (LD 1126) became law without the governor’s signature.
Serialization: Several states require home-built guns to be serialized or registered with the state; others ban unserialized frames and receivers outright. Counts differ by source as laws change.

What Gun Owners Should Know

Check your state law before buying any unfinished frame, receiver or kit. State bans and serialization rules apply regardless of the federal rule.
Under federal law, kits and frames covered by the ATF rule must go through a licensed dealer with a 4473 and background check, unless you are covered by a court order.
Making a firearm to sell, or for anyone prohibited from owning one, is a federal crime. Persons prohibited under 18 U.S.C. 922(g) may not build guns.
Every firearm must comply with the Undetectable Firearms Act and NFA rules on barrel length and full-auto function.
Keep records of where and when you obtained parts.
Related pages: Ghost Guns, 3D Printed Guns and Court Cases.

Across the Gun Websites Network

AR15 80% Lower Receiver AR15 Buyers Guide.com
80% Suppressors Suppressor Buyers Guide.com

Sources

Background and Resources

80% firearm kits, sometimes called “unfinished receivers,” refer to firearms that are partially manufactured and require some degree of assembly or finishing by the end user in order to become functional. These kits typically contain an unfinished receiver that is not classified as a firearm under federal law until it is completed.

The origin of 80% firearm kits can be traced back to the Gun Control Act of 1968, which required all firearms to have a serial number and be traceable by the Bureau of Alcohol, Tobacco, Firearms, and Explosives (ATF). However, the law also included an exemption for firearms that were not yet completed, such as unfinished receivers.

In recent years, 80% firearm kits have become increasingly popular among gun enthusiasts and hobbyists who enjoy building and customizing their own firearms. These kits are often marketed as a way to exercise Second Amendment rights while avoiding background checks and registration requirements.

However, the availability and use of 80% firearm kits have also raised concerns among law enforcement officials and gun control advocates, who argue that these kits can be used to build untraceable “ghost guns” that are difficult to detect and regulate.

In response to these concerns, some states and municipalities have enacted laws and regulations that restrict or prohibit the sale and use of 80% firearm kits. Additionally, the ATF has recently proposed new rules that would require manufacturers of unfinished receivers to include a serial number and conduct background checks on customers who purchase these kits.

The 80% map: made by hand in 2021, with the last 20% finished years later by the robots.