California Code, Penal Code - PEN § 29142

(a) For purposes of this chapter, any licensed manufacturer who produces fewer than 500 firearms in a calendar year within this state may maintain a “secure facility” by complying with all of the requirements described in Section 29141, or may design a security plan that is approved by the Department of Justice or the federal Bureau of Alcohol, Tobacco, Firearms and Explosives.

(b) If a security plan is approved by the federal Bureau of Alcohol, Tobacco, Firearms and Explosives, the approved plan, along with proof of approval, shall be filed with the Department of Justice and the local police department. If there is no police department, the filing shall be with the county sheriff's office.

(c) If a security plan is approved by the Department of Justice, the approved plan, along with proof of approval, shall be filed with the local police department. If there is no police department, the filing shall be with the county sheriff's office.