Assembly Bill 1263 (AB 1263) Understanding AB 1263: New California Firearm Rules & Compliance Guide is a California legislative measure enacted in 2025 and signed into law, Chapter 636, Statutes of 2025. It focuses on firearms regulation, specifically addressing the unlawful manufacture of firearms, the distribution of firearm-related products, and the responsibilities of firearm industry members in sales and delivery.
Understanding AB 1263: New California Firearm Rules & Compliance Guide
Purpose and Context
AB 1263 was introduced by Assembly Member Mike Gipson and co-authored by several Democratic Assembly members in February 2025. The bill was developed in response to growing concerns about unregulated firearm production, the spread of digital firearm manufacturing files, and the need for clearer standards governing firearm-related product distribution and industry conduct in California.
Key Provisions
1. Criminal and Civil Measures Against Unlawful Manufacture
The bill expands existing law by making it a misdemeanor to knowingly or willfully cause another person to unlawfully manufacture a firearm — including using a 3-D printer or CNC milling machine, the production of assault weapons, machineguns, or .50 BMG rifles.
It also broadens civil liability for people who distribute digital firearm manufacturing code (e.g., files or instructions that enable firearms fabrication) and allows those harmed by such conduct to seek compensatory damages and injunctive relief.
2. Definitions of Firearm-Related Products and Industry Standards
AB 1263 updates key definitions to include:
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Firearm accessories — such as parts designed to increase rate of fire, improve reload speed, or convert firearms into assault weapons.
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Firearm manufacturing machines — CNC milling machines, 3-D printers, and similar devices used to produce firearm parts.
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Firearm-related products — a broad category including firearms, ammunition, components, and accessories.
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Firearm industry members — entities involved in manufacturing, importing, distributing, marketing, or selling firearm-related products.
These definitions shape the legal duties and compliance expectations for businesses and individuals engaged in the firearms industry.
3. Industry Standards of Conduct and Sale/Delivery Rules
AB 1263 requires firearm industry members to:
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Establish, implement, and enforce reasonable controls to prevent sales to prohibited persons, straw purchasers, or otherwise risky buyers.
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Avoid marketing products in ways that promote unlawful manufacturing or conversion.
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Comply with civil and criminal prohibitions in selling firearm accessories and related items.
For the sale or delivery of firearm accessories, firearm barrels unattached to firearms, or firearm manufacturing machines:
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Sellers must provide a clear written notice about the criminality of unlicensed firearm manufacture and receive buyer acknowledgment.
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Buyers must show proof of identity and age (18+).
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Shipments must be labeled with “Signature and proof of identification of person aged 18 years or older required for delivery,” and delivery must occur to a matching identification address with signature verification.
These requirements aim to tighten oversight of how firearm-related products are distributed in and into California.
4. Additional Penal Code Changes
The bill also amends the Penal Code to make it illegal for persons convicted under specific firearm manufacturing offenses to own, purchase, or receive any firearm for ten years following conviction.
Legislative Process and Status
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Introduced: February 21, 2025
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Passed through Assembly and Senate committees and readings throughout 2025
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Signed and Chaptered: October 11, 2025 (Chapter 636, Statutes of 2025)
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The bill is now part of California law and will be enforced according to its provisions.
Impacts and Considerations
AB 1263 has generated significant discussion, especially among firearm owners and industry stakeholders, about how its expanded definitions and delivery requirements will affect transactions and shipping practices for firearm parts and accessories. Many smaller vendors have reportedly stopped shipping to California to avoid increased compliance burdens.
Critics argue some aspects may be overly restrictive or disrupt legitimate commerce, while supporters emphasize the bill strengthens controls on unlawful firearm manufacture and distribution. (Note: these reactions represent public debate and commentary; consult legal counsel for authoritative interpretations.)
Where to Read the Full Bill
You can view the complete bill text and history on California’s official legislative information site:
📄 Legislative Information — AB-1263 (2025-2026 Session):
https://leginfo.legislature.ca.gov/faces/billNavClient.xhtml?bill_id=202520260AB1263
Chapter: 636, Statutes of 2025
Signed by Governor: October 11, 2025
Effective: Upon enactment (with certain provisions effective January 1, 2026)
Sponsor: Assembly Member Mike Gipson
Purpose:
AB 1263 strengthens California’s laws regulating the manufacture, distribution, and possession of firearms, firearm accessories, firearm precursor parts, and digital firearm manufacturing files (“ghost guns”). The law targets both unlicensed firearm manufacturers and individuals who facilitate, aid, or promote unlawful firearm manufacture, including via digital files or 3D printing.
1. Key Definitions (Civil Code §3273.50)
AB 1263 updates the definitions for terms critical to California’s firearm laws:
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Firearm – Same as defined in Penal Code §16520.
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Firearm accessory – Attachments or devices designed to increase rate of fire, reload speed, or convert firearms into assault weapons; includes kits or parts designed to manufacture firearms.
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Firearm-related product – Firearms, ammunition, firearm components, firearm precursor parts, firearm accessories, and firearm manufacturing machines if sold, distributed, or reasonably expected to be possessed in California.
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Firearm precursor part – As defined in Penal Code §16531; includes unfinished frames or receivers.
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Firearm industry member – Any person, entity, or organization engaged in manufacture, distribution, importation, marketing, or sale of firearm-related products.
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Firearm manufacturing machine – CNC milling machines, 3D printers, or similar devices designed to manufacture firearms or components.
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Reasonable controls – Measures to prevent sales to prohibited persons, theft, misuse, and to ensure compliance with California and federal laws.
Who it affects:
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Firearm industry members (manufacturers, distributors, retailers, importers, marketers)
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Anyone using CNC or 3D printing technology to make firearms
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Purchasers of firearms, firearm parts, or accessories in California
2. Firearm Industry Standards (§3273.51)
Firearm industry members must:
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Establish, implement, and enforce reasonable controls.
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Ensure that downstream distributors or retailers also comply with reasonable controls.
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Avoid manufacturing, marketing, or selling firearm products that are abnormally dangerous or primarily designed for unlawful purposes.
Key Sale/Delivery Requirements:
Before selling or delivering a firearm barrel, firearm accessory, or firearm manufacturing machine to a California resident, industry members must:
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Provide clear notice that certain acts (e.g., manufacturing firearms without a license) are criminal.
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Obtain acknowledgment from the purchaser.
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Verify purchaser’s age (18+) and identity.
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Label shipments: “Signature and proof of identification of person aged 18 years or older required for delivery.”
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Ensure delivery address matches ID, and purchaser signs for delivery.
Exceptions:
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Federally licensed dealers or manufacturers
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Licensed ammunition vendors
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Military or law enforcement personnel on duty
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Wholesalers, forensic labs, or common carriers acting in the course of delivery duties
3. Digital Firearm Manufacturing Code (§3273.60 & §3273.61)
Definition: Digital instructions or files (CAD/CAM, 3D printing, CNC programming) used to manufacture:
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Firearms (including frames/receivers)
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Large-capacity magazines and conversion kits
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Machineguns, multiburst triggers, silencers
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Firearm accessories and barrels
Prohibitions and Liability:
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Distribution of digital firearm manufacturing code to unauthorized persons is unlawful.
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Civil remedies allow individuals harmed in California to sue for compensatory damages and injunctive relief.
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Attorney General, county, or city attorneys can impose civil penalties up to $25,000 per violation.
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Rebuttable presumption of violation if website/platform promotes unlawful distribution or use.
Who it affects:
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Website owners, digital platforms, or online sellers hosting digital firearm files
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Individuals using these files to manufacture firearms without a license
4. Criminal Liability – Unlawful Manufacture (§3273.625 & Penal Code §29186)
AB 1263 makes it a misdemeanor to knowingly or willfully:
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Cause another person to manufacture a firearm unlawfully
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Aid, abet, promote, or facilitate unlawful firearm manufacture
Unlawful manufacture includes:
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Firearms made by minors or prohibited persons
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Manufacturing ≥4 firearms per year without a license
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Manufacturing via 3D printer or CNC milling machine without a license
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Manufacturing firearms to sell or transfer to unlicensed individuals
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Creating assault weapons, machineguns, undetectable firearms, unsafe handguns, zip guns, or other generally prohibited weapons
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Producing large-capacity magazines or conversion kits
Who it affects:
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Any individual engaging in unlicensed firearm production
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Persons assisting others in unlawful manufacture
Penalties: Misdemeanor – up to 1 year in county jail, fine up to $1,000, or both
5. Misdemeanor Firearm Restrictions (§29805 Penal Code)
AB 1263 expands existing 10-year firearm ownership prohibitions to include convictions under the new law:
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Individuals convicted of §29185, §29186, §30605, §30610, §32900, §33215, §33600, and related offenses
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Violations include unlawful manufacturing or facilitating manufacturing of firearms
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Punishment: county jail ≤1 year, fine ≤$1,000, or both
Impacted population:
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Anyone convicted under these new firearm offenses (restrictions apply 10 years post-conviction)
6. Practical Implications
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Firearm industry members must implement compliance measures and verify purchaser eligibility, with civil and criminal liability for violations.
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Digital file distributors face civil liability, with damages for injuries caused by firearms manufactured from distributed code.
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Individuals manufacturing firearms without a license face new misdemeanor charges and future firearm possession restrictions.
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Delivery services must ensure proof of age, signature, and address verification for firearm-related shipments.
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Consumers and hobbyists must understand that 3D printing or CNC manufacturing of firearms or components without a license is now explicitly criminal.
7. Key Takeaways
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Law Focus: Regulating “ghost guns” and unlicensed firearm manufacture
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Enforcement Tools: Civil penalties, injunctive relief, criminal charges
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Who is Affected:
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Firearm industry members (manufacturers, sellers, distributors)
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Individuals manufacturing firearms or accessories without a license
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Online platforms distributing digital firearm manufacturing files
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Buyers of firearm accessories, barrels, or manufacturing machines in California
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Penalties: Misdemeanor charges, civil damages, and 10-year firearm restrictions for certain convictions
8. Miscellaneous
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The law is severable, so invalidity of one provision does not affect the rest.
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Some amendments interact with AB 1127 and are conditional upon both bills being enacted.
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The law does not require reimbursement to local agencies under California Constitution Article XIII B §6.
