Penal Code section 29186
(a)
It is unlawful to knowingly or willfully cause another person to engage in the unlawful manufacture of firearms, or to knowingly or willfully aid, abet, promote, or facilitate the unlawful manufacture of firearms.(b)
For the purposes of this section, the “unlawful manufacture of firearms” includes any of the following:(1)
The manufacture of a firearm by a minor, or by a person who is prohibited from owning or possessing firearms under California law.(2)
The manufacture of four or more firearms within the state in the same calendar year by an individual who is not licensed to manufacture firearms pursuant to California law, in violation of Section 29010.(3)
The manufacture of any firearm using a three-dimensional printer or computer numerical control (CNC) milling machine by an individual who is not licensed to manufacture firearms pursuant to California law, in violation of Section 29185.(4)
The manufacture of a firearm by a person who is not a federally licensed firearms manufacturer, for the purpose of selling or transferring ownership of that firearm to another person who is not a federally licensed firearms manufacturer, in violation of subdivision (d) of Section 29180.(5)
The manufacture of a firearm for the purpose of selling, loaning, or transferring the firearm to another person, with the intent to complete the sale, loan, or transfer without a required background check on the transferee initiated by a licensed firearms dealer, in violation of Section 27520.(6)
The manufacture of any of the following:(A)
Assault weapons or .50 BMG rifles, in violation of Section 30600.(B)
Firearms that are not immediately recognizable as firearms, in violation of Section 24510.(C)
Firearms that are not imprinted with a valid state or federal serial number or mark of identification, in violation of subdivision (f) of Section 29180.(D)
Large-capacity magazines or large-capacity magazine conversion kits, in violation of Section 32310 or 32311.(E)
Machineguns, in violation of Section 32625.(F)
Multiburst trigger activators, in violation of Section 32900.(G)
Short-barreled rifles or short-barreled shotguns, in violation of Section 33215.(H)
Undetectable firearms, in violation of Section 24610.(I)
Unsafe handguns, in violation of Section 32000.(J)
Zip guns, in violation of Section 33600.(K)
Any other weapon defined as a “generally prohibited weapon” under Section 16590.(c)
A violation of this section is a misdemeanor.
Source:
Section 29186, https://leginfo.legislature.ca.gov/faces/codes_displaySection.xhtml?lawCode=PEN§ionNum=29186. (updated Jan. 1, 2026; accessed Dec. 29, 2025).
