Introduction
As of 2025, the question of whether are 3d printed guns legal in washington state has a complex answer that mostly points to no. Making, owning, or putting together most firearms using a 3D printer is now heavily limited and largely against the law. This happened because of specific, recent laws that target privately made firearms. While the simple answer is "mostly no," understanding the important details of these laws is essential for any hobbyist, gun enthusiast, or concerned citizen.
This article provides informational and educational content for 2025 and is not legal advice. The laws around firearms are complex, change often, and are subject to court interpretation. You must talk with a qualified attorney in Washington state about your specific situation before taking any action related to making or owning firearms.
This guide will provide a clear roadmap to navigate this challenging legal landscape. We will begin with a summary of the current legal status, then take a deep dive into the specific Washington state laws that create these restrictions. We will also cover relevant federal laws, define key legal terms you need to know, and walk through practical scenarios to show how these laws apply in the real world.
2025 Legal Status Summary
The legal environment in Washington for 3D-printed firearms is defined by a multi-layered approach that effectively prohibits most activities common to the hobby. The state legislature has passed laws that directly address the primary characteristics of these firearms, creating a legal minefield for the uninformed.
The General Rule
Washington law now directly targets firearms that are considered "untraceable" or "undetectable." An untraceable firearm is one that lacks a serial number applied by a licensed manufacturer. An undetectable firearm is one designed to avoid metal detectors. Because the vast majority of 3D-printed firearm frames and receivers are made from polymer and start without a professionally applied serial number, they almost always fall into one or both of these heavily restricted categories. The act of creating or possessing such an item is the central focus of the state's recent prohibitions.
The "Assault Weapon" Ban
Making the issue worse is Washington's broad ban on the manufacture, import, and distribution of "assault weapons," as defined by House Bill 1240. This law is not specific to the method of manufacture, meaning it applies equally to firearms made in a factory and those printed on a home device. Many of the most popular and widely available 3D-printed firearm models are digital copies of firearms that are now explicitly defined and banned as assault weapons in the state. Therefore, even if one could overcome the "untraceable" firearm issue, manufacturing these specific models would still be illegal.
Key Prohibited Activities
To be perfectly clear, under Washington's 2025 legal framework, the following activities are generally illegal:
- Manufacturing, causing to be manufactured, or assembling an undetectable firearm.
- Manufacturing, causing to be manufactured, or assembling an untraceable firearm.
- Possessing, transporting, or receiving an untraceable firearm that was acquired after the law's effective date in 2023.
- Manufacturing, importing, or distributing any firearm that meets the state's definition of an "assault weapon."
Washington State Gun Laws
To fully understand the current situation, we must examine the two key pieces of legislation that form the foundation of Washington's regulations. These laws work together to create a comprehensive, and highly restrictive, legal environment.
HB 1739: The "Ghost Gun" Law
This law, effective in 2023, was specifically designed to close the perceived loophole of privately made, unserialized firearms, often called "ghost guns." The intent was to ensure that all firearms in the state are traceable by law enforcement. The law's provisions are direct and have profound implications for 3D printing.
It explicitly criminalizes the manufacture, assembly, sale, transfer, purchase, and possession of both "untraceable" and "undetectable" firearms. For hobbyists, the prohibition on "manufacturing" and "assembling" is the most relevant. This means the act of 3D printing a frame or receiver, or putting together a kit that uses such a part, is a prohibited act.
The law's effective date is a crucial element. While it contains some narrow provisions for firearms possessed before its passage, the general rule is that possessing an untraceable firearm you made or acquired after mid-2023 is illegal. Furthermore, the law establishes a complex process for having unserialized firearms serialized by a licensed dealer, but this process is not a simple workaround for someone looking to manufacture new firearms; it was primarily intended for existing firearms.
HB 1240: "Assault Weapon" Ban
While HB 1739 targets the nature of unserialized firearms, HB 1240 targets the characteristics and models of the firearms themselves. Codified in RCW 9.41.390, this law bans the manufacture, import, distribution, and sale of a long list of firearms defined as "assault weapons." This has a massive, and perhaps sometimes unintended, impact on 3D printing.
Under Washington law, an "assault weapon" includes:
- Over 60 specific firearm models by name, including many variants of the AR-15, AK-47, and Uzi.
- Any semi-automatic rifle that has an overall length of less than 30 inches.
- Any semi-automatic rifle that has one or more features, such as a telescoping stock, a pistol grip, a flash suppressor, or a threaded barrel.
- Any semi-automatic pistol that has one or more features, such as a threaded barrel, a second handgrip, or the capacity to accept a detachable magazine outside of the pistol grip.
Since many popular 3D-printable firearm files are for platforms like the AR-15 or for pistol frames designed to be built into configurations with these features, the act of printing these parts is considered the illegal "manufacture" of a banned assault weapon.
Federal Law Framework
It is critical to understand that state laws operate alongside a framework of federal regulations. Compliance with both is mandatory, and ignorance of one is not an excuse. In the case of 3D-printed guns, Washington's laws are significantly stricter than the general federal guidelines.
The Undetectable Firearms Act
This federal law has been in effect since 1988 and is the baseline for all firearm manufacturing. It makes it illegal to manufacture, possess, or sell any firearm that is not detectable by a standard walk-through metal detector. To comply with this act, a firearm must contain at least 3.7 ounces of metal, strategically placed. This law single-handedly makes any all-plastic 3D-printed gun federally illegal, no matter what state you are in. Any legitimate design must incorporate this amount of metal.
The Gun Control Act and "Manufacturing"
Traditionally, federal law, as interpreted by the ATF, has not prohibited a person who is legally allowed to own firearms from making a firearm for their own personal use, provided it is not for sale and complies with the Undetectable Firearms Act. This is the guidance that for many years allowed the "ghost gun" hobby to flourish.
However, this is the most critical point of confusion we must clarify: stricter state laws always supersede more permissive federal guidelines. While federal law might not prohibit making a serialized, detectable pistol for personal use, Washington state law does prohibit it if that firearm is considered "untraceable" from the moment of its creation.
Federal vs. Washington Law Comparison
This table shows the critical differences between the general federal guidance and Washington's specific, more restrictive laws as of 2025.
| Feature | Federal Law (General Guideline) | Washington State Law (As of 2025) |
|---|---|---|
| Personal Manufacturing | Generally permissible for non-prohibited persons, not for sale. | Highly restricted. Illegal if the firearm is "untraceable" or an "assault weapon." |
| Serialization | Not required for personal builds (not intended for sale). | Effectively required, as "untraceable" firearms are illegal to make or possess. |
| Undetectable Firearms | Illegal. Must contain at least 3.7 oz of metal. | Illegal. State law aligns with and reinforces this federal prohibition. |
| "Assault Weapons" | No federal ban on manufacturing for personal use (as of 2025). | Illegal to manufacture, import, or distribute. |
Understanding the Legal Concepts
To navigate this topic, you must understand how the law defines certain terms. These definitions are not obvious and form the basis of any potential criminal liability. Learning to think with these concepts is the first step toward making informed and safe decisions.
What Is a "Firearm"?
In the eyes of the law, the "firearm" is not always the complete weapon. Legally, the part of the gun that houses the firing mechanism—the frame or receiver—is what is regulated. This means that 3D printing just the lower receiver of an AR-15 or the frame of a pistol is legally equivalent to manufacturing a firearm. You do not need to build the entire weapon to have broken the law; printing the regulated component is enough.
"Untraceable" vs. "Undetectable"
These two terms are not interchangeable and address different concerns.
* An untraceable firearm is one that does not have a serial number applied by a federally licensed manufacturer. This is the core definition of a "ghost gun." The purpose of serial numbers is to allow law enforcement to trace a weapon from the manufacturer to the first retail sale and, in some cases, beyond. A privately made firearm lacks this history, making it "untraceable."
* An undetectable firearm is one that cannot be found by standard security screening equipment like metal detectors. This is linked to the federal requirement for 3.7 ounces of metal.
"Manufacturing" vs. "Assembling"
A common question we see is where the legal line is drawn between these two actions. Under Washington law, especially HB 1739, there is very little distinction. The law prohibits a person from manufacturing, causing to be manufactured, or assembling an untraceable firearm. This broad language covers the entire process, from creating a receiver using a digital file and a 3D printer to putting together a parts kit that includes an unserialized frame you purchased or printed. Both are prohibited acts.
What Is "Possession"?
Possession is another legal term with a broader meaning than its everyday use. It can be "actual" or "constructive." Actual possession means the item is on your person or within your immediate physical control. Constructive possession means the item is not on your person, but you have knowledge of it and it is under your control. For example, an illegal 3D-printed receiver stored in your garage, your car's trunk, or a safe in your home could all be considered constructive possession, carrying the same legal weight as if it were in your pocket.
Practical Scenarios in 2025
To make this complex legal information more concrete, let's apply it to some hypothetical scenarios. These are for educational purposes only and show how the laws we've discussed would likely be interpreted.
Scenario 1: Printing an AR-15 Lower
- Scenario: A hobbyist in Seattle downloads a file for an AR-15 lower receiver and successfully prints it on their home 3D printer for personal use.
- Analysis: This action is very likely illegal on at least two separate grounds. First, by printing the receiver, they have illegally manufactured an "untraceable firearm" in violation of HB 1739. Second, the AR-15 is specifically named and defined as a banned "assault weapon" under HB 1240. The act of manufacturing it, regardless of method, is a prohibited act.
Scenario 2: Printing a Pistol Frame
- Scenario: A resident in Spokane prints a Polymer80-style frame, which is compatible with Glock parts, to build a personal handgun.
- Analysis: This is also illegal. The moment the frame is printed, it is an "untraceable firearm," and manufacturing it violates HB 1739. Furthermore, depending on the final configuration of the pistol—for example, if it is built with a threaded barrel to accept a compensator or suppressor—it could also be classified as an "assault weapon" under the specific pistol definitions in HB 1240, adding another layer of illegality.
Scenario 3: Storing Gun Files
- Scenario: A person downloads several digital CAD files for 3D-printable firearms but does not own a 3D printer and has not printed anything.
- Analysis: This is a high-risk gray area. As of 2025, the act of merely possessing digital data is not explicitly criminalized in the same way as manufacturing. However, prosecutors could potentially use the possession of these files as strong evidence of intent to manufacture, which is illegal. From a risk-management perspective, this is playing with fire and could easily invite legal scrutiny.
Scenario 4: Printing a Non-Firearm Part
- Scenario: An enthusiast prints a non-regulated part, such as a custom grip, a stock, or a forend for a firearm they already legally own.
- Analysis: This is generally legal, but with a significant and dangerous caveat. If the part is intended for a firearm that is, or would become, an illegal "assault weapon," then printing that part could be interpreted as a step in the process of manufacturing or creating an illegal weapon. For example, adding a pistol grip to a previously featureless semi-automatic rifle could turn it into an illegal assault weapon. The context and the nature of the firearm the part is for matter immensely.
Conclusion: The Legal Reality
As we have detailed, the legal reality in Washington state as of 2025 is clear: the state has one of the most restrictive environments in the United States for 3D-printed firearms. The powerful combination of the "ghost gun" law (HB 1739) and the comprehensive "assault weapon" ban (HB 1240) works to make nearly all common 3D-printed firearm projects illegal.
We must emphasize that violations of these laws are not minor infractions; they are serious criminal offenses that can carry severe penalties, including hefty fines and felony convictions with long-term consequences for employment, housing, and your fundamental rights. The legal landscape is a minefield for hobbyists, and the risks of a misstep are life-altering.
Therefore, the only responsible advice is to err on the side of extreme caution. Before exploring this hobby in any capacity that involves printing regulated parts, we strongly urge you to seek personalized legal advice from a qualified firearms attorney in Washington state. The question of are 3d printed guns legal in washington state has been answered clearly by the legislature, and the answer is overwhelmingly no.