80 Percent Lower Laws Reviewed (State & Federal, 2019)

Posted by 80-Lower on Jul 16th 2019

80 Percent Lower Laws Reviewed (State & Federal, 2019)

We've found the latest 80 percent lower laws that may affect your black rifle project in 2019. We compiled information from the Gun Control Act of 1968, the Bureau of Alcohol, Tobacco, and Firearms, state agencies and legislatures, and their current laws.

DISCLAIMER: We love guns, but we're not lawyers. Gun laws are constantly changing. This guide cannot and should not be taken as legal counsel or legal advice. Always do your part to protect yourself. Research the laws before you buy, build, or own a firearm in your state. If you're unsure, consult an attorney.

Terms and Definitions

What is an 80 percent or "unfinished" receiver?

Directly from the Bureau of Alcohol, Tobacco, and Firearms:

"80% receiver,” “80% finished,” “80% complete,” and “unfinished receiver” are all terms referring to an item that some may believe has not yet reached a stage of manufacture that meets the definition of firearm frame or receiver found in the Gun Control Act of 1968 (GCA). These are not statutory terms or terms ATF employs or endorses."

What is a stripped lower receiver?

A stripped lower receiver can be used to build a functional AR-15. It is considered a firearm by the Bureau of Alcohol, Tobacco, and Firearms. A partially-completed or finished 80% lower is also considered a firearm by the ATF. An 80% lower that is not machined in any way is considered a receiver blank.

What is a receiver blank?

A receiver blank is a piece of metal or polymer that resembles a firearm, but isn't one yet. This is how the ATF handles classifying receiver blanks and firearms:

"Receiver blanks that do not meet the definition of a "firearm" are not subject to regulation under the GCA. The ATF has long held that items such as receiver blanks, "castings" or "machined bodies" in which the fire-control cavity area is completely solid and un-machined have not reached the "stage of manufacture" which would result in the classification of a firearm per the GCA."

See a visual comparison from the ATF:

Federal 80 Percent Lower Laws

Let's start with the biggest questions and federal laws, then we'll get into state laws:

Do I need an FFL to finish an 80 percent lower?

"No, a license is not required to make a firearm solely for personal use. However, a license is required to manufacture firearms for sale or distribution. The law prohibits a person from assembling a non–sporting semiautomatic rifle or shotgun from 10 or more imported parts, as well as firearms that cannot be detected by metal detectors or x–ray machines. In addition, the making of an NFA firearm requires a tax payment and advance approval by ATF." - Bureau of Alcohol, Tobacco, and Firearms

[18 U.S.C. 922(o), (p) and (r); 26 U.S.C. 5822; 27 CFR 478.39, 479.62 and 479.105]

Do I need to serialize my 80% lower?

No, unless you live in California or you're building a Title II firearm, like a short-barreled rifle.

Federal law says that a firearm made for personal use does not need to have a serial number or identifying engravings. Here's what the ATF recommends:

"Additionally, although markings are not required on firearms manufactured for personal use (excluding NFA firearms), owners are recommended to conspicuously place or engrave a serial number and/ or other marks of identification to aid in investigation or recovery by State or local law enforcement officials in the event of a theft or loss of the privately owned firearm."

We agree. It's always good practice to make your gun uniquely identifiable in the rare event it's lost or stolen. Even a simple, hand-engraved serial number is sufficient.

What are the requirements for serializing my lower?

If you're building an SBR or you live in a state that requires serialization, you must adhere to the following guidelines. Your receiver should be engraved with the following:

  1. Serial number (provided by the DOJ in California)
  2. Caliber ("MULTI" no longer works, it must be the caliber)
  3. Manufacturer's name (that's you)
  4. Manufacturer's city and state (where you live)
  5. Optional: Firearm model

Your serial number and engravings must be at least 0.003" deep and the text size must be at least 0.125" high. Because an 80 percent lower isn't a considered a firearm, any machinist or shop with the right equipment can serialize your incomplete lower for you.

Can I sell or transfer my completed lower?

Yes, you can transfer or sell the lower you built as an individual.

But you have to ensure your actions aren't being interpreted as "manufacturing with the intent to sell".

The ATF says that you cannot make an 80 percent lower into a firearm with the intent of selling it. That's the key: Intent. And to make things more confusing, the ATF and Federal law have plenty of legalese, statutes, and wordy sections about how "manufactured firearms must be serialized" and "only an FFL can make and sell firearms".

But these regulations only apply to manufacturers, those in the business of building guns. You're an individual building your gun for personal use. So, yes, you can sell your completed 80 percent lower to someone later if you didn't originally intend to sell it.

If you bought 10 lowers, machined them all, and posted them for sale online, this would likely be interpreted as manufacturing with intent to sell. Use common sense here.

Do I need to serialize my lower if I sell it?

Short answer: No.

Long answer: You should.

When asked, "I want to sell my completed 80 percent lower, do I need to serialize it when I sell it or transfer it?" the ATF had this to say:

"Firearm markings are only required by those who are licensed importers, license manufacturers, and those who make an NFA firearm for personal use. Those markings would be made the time of import, manufacture, or when an NFA firearm was made. Under Federal law, no markings would be required in your circumstance."

The NFA legalese doesn't apply if you're building a regular AR-15 rifle or pistol. This only applies if you've built and want to sell an SBR or other NFA item.

But that doesn't mean you shouldn't serialize your lower anyway. Once you sell it, you'll no longer have any control over that firearm. The buyer might sell it. It's unlikely, but it could get stolen. You want to make sure your hands are clean of that weapon once you no longer possess it. The safest way to do that is to serialize it and have the sale recorded with an FFL transfer, not just a private purchase.

State 80 Percent Lower Laws

Some states have enacted restrictions, legislation, or outright bans on receiver blanks and homemade guns. Below we've listed the current laws in 2019 that govern (or restrict) 80% lowers by state. We also included info about building 80% in lowers states that readers ask about, like Texas, New Jersey, and Washington.


Do I need an FFL or serial number for my 80% lower?

You do not need an FFL to buy or own an 80% lower in California.

You need a serial number engraved before you finish your lower.

Because it is not considered a firearm, a receiver blank can't be transferred by an FFL and it isn't regulated by the Gun Control Act, the ATF, or any other agency or Federal law (at this time). This only applies to buying and owning an 80 percent lower, not machining it or making a firearm.

Serial number requirements:

In July 2016, California enacted Bill AB 857. This bill required all completed firearms in the state to have an engraved serial number by January 1, 2019. If you're a new builder living in California, you'll need to have your receiver engraved before you complete it and turn it into a firearm. Here is a quick summary of the steps you must take:

  1. Fill out a Personal Firearms Elibility Check (PFEC) application
  2. Submit your PFEC application to the California DOJ
  3. Register on the California Firearms Application Reporting System (CFARS)
  4. Complete and submit a Unique Serial Number Application in CFARS
  5. Wait for your unique serial number to arrive in the mail
  6. Get your 80 percent lower serialized

Then you can build it. We have a complete guide on how to serialize your 80 percent lower in California. It includes instructions and links to all the paperwork and systems you need to go through to apply.

New York

Can I build an 80% lower in New York?

Yes, you can. New York has enacted The SAFE Act, which regulates how an AR-15 must be configured in New York to be legal. But there are currently no laws governing the sale, ownership, or building an 80% lower by itself. You can read here how one New Yorker legally built his own AR-15 using an 80% lower.

Making your build compliant

New York has banned specific AR-15 models by manufacturer, too. Attempting to describe how to build a NY-compliant AR-15 is beyond the scope of this article, but you can learn everything you need to know about completing your build by navigating New York's SAFE Act website.


Are there state laws restricting the 80% lower in Texas?

No. Texas does not currently regulate receiver blanks, 80% lowers, or AR-15s with any greater restrictions than the ATF or Federal law.

For a little entertainment, you can read about how some Second Amendment supporters decided to start building 80% lowers and AR-15s right on the steps of the State Capitol. Texas is (thankfully) quite black rifle- and gun-friendly.

New Jersey

Can I build an 80% lower in New Jersey?

Unfortunately, no.

New Jersey's Attorney General Gurbir Grewal "demanded" that manufacturers stop selling any firearm receiver blanks in the state. Grewal's logic is shaky, to say the least: "Fraud is committed because the makers do not disclose that possessing a firearm classified under state law as an unregistered "assault weapon" in New Jersey is a crime."

Except receiver blanks aren't assault weapons. They're not even firearms. Nonetheless, N.J.S.A. 2C:39-9g restricts us and any other makers from selling to New Jersey residents.


Can I build a receiver blank in Washington state?

As of now, the answer is yes.

Recent legislation was passed - Substitute House Bill 1739 - which effectively bans the manufacturing of 3D-printed firearms. It also bans the manufacture and ownership of "undetectable" firearms. The bill defines an undetectable firearm as:

"Any firearm that is not as detectable as 3.7 ounces of 17-4 PH stainless steel by walk-through metal detectors or magnetometers commonly used at airports or any firearm where the barrel, the slide or cylinder, or the frame or receiver of the firearm would not generate an image that accurately depicts the shape of the part when examined by the types of X-ray machines commonly used at airports."

This definition bans polymer receiver blanks for any firearm, including the AR-15 and Glock. The bill also defines weapons built using a receiver blank as an "untraceable" firearm:

"Any firearm manufactured after July 1, 2019, that is not an antique firearm and that cannot be traced by law enforcement by means of a serial number affixed to the firearm by a federally licensed manufacturer or importer."

SHB 1739 only restricts shooters from building a firearm using a receiver blank with the intent to sell it. But simply building one for personal use is not illegal at this time. This is the same position the ATF has taken on the matter.


We hope this guide provides a good starting point and source of information for your own 80% lower build. Keep in mind that state and federal laws are changing on a regular basis. Gun laws are the most volatile, too. Always perform your own research and consult with an attorney to fully ensure you're operating within the law. If you have questions, feel free to contact us. We're standing by and we're happy to help!

DISCLAIMER: If you are new to the world of DIY gun building, you likely have a lot of questions and rightfully so. It’s an area that has a lot of questions that, without the correct answers, could have some serious implications. At 80-lower.com, we are by no means providing this content on our website to serve as legal advice or legal counsel. We encourage each and every builder to perform their own research around their respective State laws as well as educating themselves on the Federal laws. When performing your own research, please be sure that you are getting your information from a reliable source.