Regulations: Firearm Barrels

Summary:

The Legislature has enacted several laws designed to address the proliferation of unlawfully manufactured ghost guns, which are unserialized firearms produced by individuals who do not have a valid license to manufacture firearms. Ghost guns are typically produced using products sold without eligibility checks or sale records, including machines such as three-dimensional printers and/or firearm build kits, accessories, and components. One such component is a firearm barrel, defined by Penal Code section 16525(a) as “the tube, usually metal and cylindrical, through which a projectile or shot charge is fired.” Because the remaining parts of a firearm may be more easily produced by consumer-level three-dimensional printers, the unregulated sale of firearm barrels without eligibility checks allowed minors and prohibited individuals to illegally manufacture firearms without undergoing the background check that is normally required for firearm purchasers in California.

In 2025, the Legislature passed SB 704, codified at Penal Code section 33700, which places conditions and requirements on the purchase, sale, or transfer of firearm barrels. Penal Code section 33700, subdivision (e) and (h) authorize the Department to adopt regulations to implement the statute. Penal Code section 33700, subdivision (a)(1) provides that a firearm barrel shall not be sold or transferred unless that transaction is completed in person by a licensed firearms dealer. Starting July 1, 2027, a firearm barrel “shall not be sold or transferred unless . . . the licensed firearms dealer has conducted an eligibility check . . . in a manner prescribed by the Department of Justice” to determine whether the person attempting to purchase the firearm barrel is authorized to do so. (Pen. Code, § 33700, subd. (a)(2).) The statute exempts a number of sales or transfers, including those to federal, state, and local law enforcement agencies, and those to federal firearms licensees, from this process. (Pen. Code, § 33700, subd. (g).)

The purpose of these regulations is to provide instructions for licensed firearms dealers to initiate the firearm barrel eligibility checks required by the statute and to fulfill purchases or transfers for people who pass the eligibility checks. The regulations will assist the regulated industry and the public to avoid engaging in unlawful purchases or transfers of firearm barrels.

NOTE: Regulation documents prepared by the Department may contain markup including underline, strikethrough, or highlight. While these documents are ADA-compliant, upon request, the Department can prepare a more screen reader-friendly version of these documents with annotations that explain the marked changes. Please submit all requests to regulations@doj.ca.gov.

Notice Register Publication Date: August 7, 2026

Status of the Proposal: This rulemaking is undergoing a 45-day public comment period. Any person or their authorized representative may submit written comments regarding the proposed regulatory action. The written comment period closes at 5:00 pm on September 22, 2026. All timely comments that specifically pertain to the proposed regulations will be reviewed and responded to by Department staff. Comments may be submitted by mail or email to:

  • Mail written comments:

Department of Justice
P.O. Box 160487
Sacramento, CA 95816


The information below relates to recent rulemaking activity, including links to the regulations text and associated documents. Any person who has submitted a comment regarding a proposed action has the right to request a copy of the Final Statement of Reasons. The Final Statement will also be posted to this webpage upon completion of this rulemaking.

Public Notice and Related Documents