Washington State Firearms Laws: HB 1240 and Beyond

In 2023, Washington became the 10th state to broadly ban the sale and manufacture of firearms classified as assault weapons, per House Bill 1240, codified under Rev. Code Wash. (ARCW) Chapter 9.41 as amended by 2023 HB 1240.

Key Point: The law does not ban possession. According to Giffords Law Center, Washington does not ban or regulate the possession of assault weapons -- only their sale, manufacture, import, and distribution. You can legally inherit an assault weapon. You can also sell one you already own, but only to a federally licensed gun dealer.

The law defines "assault weapon" broadly. Named models -- including AR-15s -- are explicitly listed. Beyond that list, the definition sweeps in:

• Semiautomatic rifles under 30 inches in overall length
• Semiautomatic centerfire rifles with a detachable magazine and one or more of: pistol grip detached from the stock, thumbhole stock, folding or telescoping stock, forward/vertical/angled grip, flash suppressor or sound suppressor, muzzle brake or recoil compensator, threaded barrel, grenade or flare launcher, or barrel shroud
• Semiautomatic centerfire rifles with a fixed magazine over 10 rounds
• Semiautomatic pistols with a detachable magazine plus a threaded barrel, second hand grip, barrel shroud, or magazine well outside the pistol grip
• Semiautomatic shotguns with a folding stock, detached pistol grip, thumbhole stock, forward grip, fixed magazine over 7 rounds, or a revolving cylinder
• Conversion kits or parts that can be used to assemble or convert a firearm into one of the above

If your semi-auto rifle has a detachable mag and a threaded barrel, read that list carefully -- it's a features test, and Washington's version casts a wide net.

The Legal Fight Over HB 1240

The law is being challenged in court, and that fight isn't over. The Silent Majority Foundation, along with gun sellers in Moses Lake and Ephrata and several individuals, sued in Thurston County Superior Court in 2023, arguing the ban violates the Washington State Constitution's right to bear arms provision:

"The right of the individual citizen to bear arms in defense of himself, or the state, shall not be impaired."

In November 2025, Thurston County Superior Court Judge Christine Schaller upheld the law, siding with the state's argument that assault weapons are not protected by the state constitution and that lawmakers can regulate weapons disproportionately used in mass shootings. Per the Washington State Standard, federal judges in both western and eastern Washington had previously denied preliminary challenges as well.

The Silent Majority Foundation has promised an appeal. Those federal cases have been paused pending an appeals court decision on California's assault weapons ban, which could set precedent for Washington.

At the U.S. Supreme Court level, conservative justices have expressed interest in taking up an assault weapons ban case, but the Court declined to hear one in 2025. The Bellevue-based Second Amendment Foundation has urged the Court to take up a challenge to a local ban in Cook County, Illinois. The issue remains unsettled nationally.

What this means for you: The ban is in effect and being enforced. Dealers in Washington cannot sell you a newly manufactured AR-15 or other named/feature-qualifying firearms right now. That could change on appeal, but betting on a court reversal before you make a purchase is not a plan.

Washington also bans the manufacture, import, distribution, sale, or offer for sale of large capacity magazines under RCW 9.41.370.

"No person in this state may manufacture, import, distribute, sell, or offer for sale any large capacity magazine, except as authorized in this section."

The statute carves out narrow exceptions:

• Licensed firearms manufacturers selling to U.S. Armed Forces, Washington state military branches, or in-state law enforcement agencies
• Licensed dealers selling to the same military and law enforcement buyers
• Licensed dealers acquiring magazines from a legally authorized person for the purpose of selling or transferring to someone who does not reside in Washington

There is no private-citizen exception. Violating RCW 9.41.370 is a gross misdemeanor under chapter 9A.20 RCW. The law was enacted in 2022 (2022 c 104 s 3).

The legal challenge to this law has also failed -- so far. According to the Washington State Standard, the Washington State Supreme Court upheld the large capacity magazine ban in 2025. The Silent Majority Foundation has since asked the U.S. Supreme Court to review that decision. As of December 2025, that petition was pending.

Key Point: Like the assault weapons sale ban, the magazine ban targets commercial transactions and manufacture -- not simple possession of magazines you already owned before the law took effect. But source material does not specify a possession grandfather clause in detail, so consult an attorney if you have questions about magazines you currently own.

Before HB 1240 came along, Washington voters passed Proposition 1639 in 2018, effective July 1, 2019. This created a separate regulatory layer for what the initiative calls "semiautomatic assault rifles" -- defined as any rifle that uses a portion of the firing cartridge's energy to extract the case and chamber the next round, requiring a separate trigger pull for each shot. That definition covers effectively all semiautomatic rifles.

The restrictions from Proposition 1639, per Giffords Law Center citing ARCW § 9.41.240 and § 9.41.092, include:

The training requirement is not a quick formality. Per Giffords citing 2023 HB 1143, qualifying safety training must cover:

• Basic firearms safety rules
• Firearms and children, including secure storage
• Suicide prevention
• Secure storage to prevent unauthorized access
• Safe handling
• State and federal firearms laws, including prohibited transfers
• Use of deadly force for self-defense under state law
• Conflict avoidance and managing violent confrontations
• Stories from individuals with lived experience in the above topics

If you're buying any firearm in Washington -- handgun or long gun -- you need documentation of qualifying safety training completed within the previous five years. Plan ahead; this isn't something you knock out the afternoon before your purchase.

Possession Rules for 18-20 Year Olds

Under Proposition 1639, adults between 18 and 21 can possess semiautomatic rifles only in specific locations. Outside of their home, fixed business, or property they control, transport is limited -- the firearm must be unloaded and in secure storage or secured with a trigger lock, and only for the specific purposes of:

• Moving to a new home
• Traveling between home and property under their control
• Selling or transferring the firearm

This is a meaningful restriction. An 18-year-old who takes a semi-auto rifle to the range is in a legal gray zone under this law. Talk to an attorney before doing so.

Washington's waiting period now applies to all firearm purchases. It started with semiautomatic rifles under Proposition 1639 and was extended to all firearms as of 2024, per Giffords Law Center. A dealer must wait 10 days before delivering any firearm after the purchase transaction.

This applies whether you're buying a hunting rifle, a shotgun, or a handgun. If you're in a situation where you believe you need a firearm immediately for personal safety, Washington law does not provide an emergency override to this waiting period based on source material available. Consult an attorney for your specific situation.

Washington is building a permit-to-purchase system that takes effect in 2027, per the Washington State Standard. Lawmakers passed the law in 2025. Source material does not detail the full requirements of the permit system, but the Standard notes it is "controversial" and that the state expects legal challenges once it takes effect.

This is worth watching. A permit-to-purchase system adds a government approval layer before you can buy a firearm -- separate from the federal background check at the point of sale. If you're in Washington and buy firearms regularly, track this legislation as 2027 approaches.

For all the restrictions Washington has layered on, the state has drawn a line at possession. Per Giffords Law Center:

• Owning an assault weapon you already have is legal
• Inheriting an assault weapon is legal
• Selling an assault weapon you own to a federally licensed dealer is legal

What you cannot do is buy a new one from a dealer, import one, or have one manufactured. Washington's approach is to choke off the supply chain without confiscating what's already in private hands -- at least under current law.

Two organizations have been most active in the legal battles over Washington's gun laws.

The Silent Majority Foundation, based in Pasco, Washington, filed the HB 1240 lawsuit in Thurston County and has challenged the magazine ban as well. The organization was formerly led by Pete Serrano, who ran unsuccessfully for Washington state attorney general in 2024 and was subsequently named interim U.S. attorney for Washington's Eastern District by President Trump in August 2025. Per the Washington State Standard, Serrano is not affiliated with the foundation while serving as U.S. attorney.

The Second Amendment Foundation, based in Bellevue, has been pushing at the federal level -- most recently urging the U.S. Supreme Court to take up the Cook County, Illinois assault weapons ban case, which could create precedent applicable to Washington.

The Alliance for Gun Responsibility has supported the state's laws and praised each court victory upholding them.

Gov. Bob Ferguson spent years as Washington state attorney general advocating for HB 1240, motivated in significant part by a 2016 shooting at a Mukilteo house party that killed three teenagers and injured another, per the Washington State Standard. Ferguson is now governor.

The federal government banned the manufacture of assault weapons in 1994 and let that prohibition expire after 10 years. Washington's law fills that gap at the state level -- and unlike the federal ban, has so far survived initial court challenges.

Washington is one of 10 states with a broad semiautomatic firearms sale/manufacture ban as of December 2025.

This is one of the most actively litigated areas of firearms law in the country right now, and Washington is near the center of it.

The outcome of the California case in federal appeals court is probably the most consequential near-term event for Washington gun owners. If that court strikes down California's ban, it creates strong precedent that could unwind HB 1240 as well. If it upholds the ban, expect the fight to shift to the U.S. Supreme Court.

The bottom line: Washington's gun laws are among the most restrictive in the country and are currently in force. The sale ban, magazine ban, waiting period, and training requirement are all active law. The permit-to-purchase system arrives in 2027. Every one of these laws faces ongoing legal challenges -- but until a court says otherwise, they govern what you can buy and how.

If you have specific questions about what you can legally own, transport, or purchase under current Washington law, talk to a Washington-licensed attorney who practices firearms law. This area is moving fast.

• https://washingtonstatestandard.com/2025/12/04/was-assault-weapons-ban-survives-another-round-in-court-but-its-unlikely-to-be-the-last/
• https://giffords.org/lawcenter/state-laws/assault-weapons-in-washington/
• https://app.leg.wa.gov/RCW/default.aspx?cite=9.41.370
• https://app.leg.wa.gov/billsummary/?BillNumber=1240&Year=2023&Initiative=false

Last Updated: March 30, 2026