Washington State has implemented a complex and evolving landscape of firearm regulations, with a significant focus on restricting certain types of firearms and their components. Understanding these restrictions is crucial for responsible firearm ownership and compliance with state law. This article delves into the specific gun parts that are banned or heavily regulated in Washington State, providing clarity on the legal framework surrounding these items.
The Ban on Assault Weapons and High-Capacity Magazines
At the forefront of Washington’s firearm restrictions is the ban on “assault weapons” and “high-capacity magazines.” This legislation, effective from April 22, 2022, significantly impacts what firearm components individuals can legally possess or purchase within the state.

Defining “Assault Weapons”
The definition of an “assault weapon” under Washington law is broad and encompasses a range of semi-automatic rifles, pistols, and shotguns that meet specific criteria. The ban targets firearms that possess certain military-style features designed to enhance their lethality or ease of rapid firing. Key features that can classify a firearm as an “assault weapon” include:
- Pistol Grip: A grip that protrudes conspicuously beneath the action of the weapon. This distinguishes it from traditional hunting-style rifles.
- Folding or Telescoping Stock: Stocks that can be collapsed or extended, making the firearm more compact for concealment or easier to maneuver.
- Magazine Capacity: The ability to accept a detachable magazine with a capacity of more than 10 rounds. This is a critical component in the definition.
- Threaded Barrel: A barrel designed to accept a flash suppressor, forward pistol grip, or silencer.
- Barrel Shroud: A shroud that encircles the barrel, providing heat protection to the shooter’s hand.
- Cosmetic Features: Even certain cosmetic features, such as a shroud that is attached to or that forms part of the barrel or receiver, can contribute to the classification.
It is important to note that the law employs a combination of features. A firearm is classified as an assault weapon if it is a semi-automatic rifle, pistol, or shotgun that has at least one of the enumerated features. This comprehensive definition aims to capture a wide array of firearms that could be considered paramilitary in nature.
The Restriction on High-Capacity Magazines
Closely linked to the assault weapon ban is the prohibition on certain magazines. Washington State law defines a “large-capacity magazine” as any magazine, belt, drum, feed strip, or similar device that has the capacity to accept, or that can be readily converted to accept, more than 10 rounds of ammunition. This prohibition applies to magazines manufactured after the effective date of the ban.
Possession and Transfer Restrictions
The ban on large-capacity magazines affects both possession and transfer. Individuals who legally possessed these magazines before the ban’s effective date are generally allowed to retain them, provided they register them with the Washington State Patrol within a specified timeframe. However, the sale, manufacture, or importation of new large-capacity magazines is prohibited. This means that any magazine purchased or manufactured after April 22, 2022, that can hold more than 10 rounds is illegal in Washington State.
What Constitutes a “Banned Part”?
The legislation effectively bans the possession and transfer of certain components that would enable a firearm to meet the definition of an assault weapon or function as a high-capacity magazine. Therefore, “banned parts” in this context refer to:
- Detachable Magazines exceeding 10 rounds: These are the most direct “parts” banned by the high-capacity magazine restriction.
- Components designed to convert a firearm into an assault weapon: While the law bans the complete “assault weapon,” it also implicitly restricts parts that are specifically designed for or integral to the assembly or modification of such weapons. This can include:
- Receivers: Specifically, stripped or semi-finished receivers that are intended to be completed into an assault weapon.
- Pistol Grips: Grips that meet the specific definition of a pistol grip as outlined in the law.
- Folding or Telescoping Stocks: Stocks designed to allow for rapid adjustment or concealment.
- Threaded Barrels: Barrels with threads intended for accessories like flash suppressors or silencers.
- Barrel Shrouds: Components designed to protect the shooter from barrel heat.
- Certain muzzle devices: Flash suppressors and similar attachments that are often indicative of an assault weapon configuration.
It’s crucial to understand that the intent behind the possession of these parts can be a factor. If a person possesses multiple components that, when assembled, would constitute an assault weapon or a firearm with a high-capacity magazine, it can raise legal scrutiny.
Regulation of “Other” Weapons
Beyond the assault weapon and high-capacity magazine bans, Washington State law also addresses a category of firearms often referred to as “other” weapons. These are firearms that, while not fitting the precise definition of a rifle, shotgun, or pistol, are designed to be fired from the shoulder or the hand and are capable of expelling a projectile by the action of an explosive.

Short-Barreled Rifles and Shotguns (SBRs/SBSs)
The law specifically targets short-barreled rifles and shotguns. A rifle is generally defined as a firearm designed to be fired from the shoulder and to be fired with a rifled barrel. A shotgun is a firearm designed to be fired from the shoulder and to be fired with a smooth bore.
- Short-Barreled Rifle: A rifle with a barrel less than 16 inches in length, or a rifle with an overall length of less than 26 inches.
- Short-Barreled Shotgun: A shotgun with a barrel less than 18 inches in length, or a shotgun with an overall length of less than 26 inches.
Possession of an SBR or SBS is prohibited unless it has been registered in accordance with federal National Firearms Act (NFA) regulations and Washington State requirements. This typically involves a federal tax stamp and a lengthy approval process. Therefore, any part that would enable a standard rifle or shotgun to be converted into an SBR or SBS, such as a barrel shorter than the legal minimum or a stock that dramatically reduces the overall length, falls under strict regulation.
Destructive Devices
Washington law also classifies “destructive devices” as prohibited weapons. This category is broad and can include:
- Bombs, grenades, rockets, missiles, and similar devices: Any explosive or incendiary device.
- Firearms designed or redesigned to expel a projectile by the action of an explosive, with a caliber greater than .50 inches: This is a significant restriction on large-caliber firearms.
- Any combination of parts designed or intended for use in converting any device into a destructive device, and from which a destructive device may be readily assembled.
This last point is critical for understanding banned parts. It means that if a collection of components is clearly intended for the construction of a destructive device, even if individually they might not be inherently illegal, their possession can be prohibited.
Accessories and Modifications
The regulatory framework extends to accessories and modifications that can alter a firearm’s functionality or appearance to align with banned categories.
Flash Suppressors and Muzzle Brakes
While not all flash suppressors or muzzle brakes are banned outright, they become restricted when attached to a firearm that is classified as an assault weapon. If a barrel is threaded and designed to accept a flash suppressor, and the firearm meets other assault weapon criteria, then the combination of the barrel and suppressor can lead to the firearm being deemed illegal. Consequently, the possession of a threaded barrel specifically intended for an assault weapon, or a flash suppressor designed for such an application, can be problematic.
Bump Stocks and Similar Devices
Bump stocks, which allow a semi-automatic firearm to fire at a rate similar to that of a machine gun by leveraging the firearm’s recoil, are explicitly banned in Washington State as part of the assault weapon definition. This ban encompasses devices that are designed to increase the rate of fire of a semi-automatic firearm. Therefore, any part or device that functions as a bump stock or a similar mechanism to achieve rapid fire is considered a banned component.
Legal Nuances and Compliance
Navigating Washington’s firearm laws requires careful attention to detail. The definitions are precise, and even seemingly minor components can have significant legal implications.

Key Considerations for Compliance
- Magazine Capacity: Always ensure that any detachable magazine in your possession holds no more than 10 rounds.
- Assault Weapon Features: Be aware of the features that define an “assault weapon” and avoid possessing firearms that combine these features with semi-automatic action.
- Registration: For any regulated items like SBRs or SBSs that you legally possess under federal law, ensure they are properly registered with both federal and state authorities.
- Intent: While not always explicitly stated, the legal system often considers the intent behind the possession of firearm parts. Possessing components that clearly facilitate the illegal modification or assembly of banned firearms can lead to legal repercussions.
- Federal vs. State Law: It is essential to remember that state laws can be more restrictive than federal laws. Always adhere to the most stringent regulations applicable in Washington State.
- Consult Legal Experts: The landscape of firearm laws is subject to change and interpretation. For definitive guidance and to ensure full compliance, it is always advisable to consult with a qualified legal professional specializing in firearm law in Washington State.
By understanding the specific gun parts that are banned or regulated in Washington State, firearm owners can make informed decisions, ensure their compliance with the law, and contribute to a safer community. The state’s legislative efforts aim to balance Second Amendment rights with public safety concerns, and staying informed is paramount for all firearm owners.
