California Code, Penal Code - PEN § 17705

(a) The provisions listed in Section 16590 do not apply to any firearm or ammunition that is a curio or relic as defined in Section 478.11 of Title 27 of the Code of Federal Regulations and that is in the possession of a person permitted to possess the items under Chapter 44 (commencing with Section 921) of Title 18 of the United States Code and the regulations issued pursuant thereto.

(b) Any person prohibited by Chapter 1 (commencing with Section 29610), Chapter 2 (commencing with Section 29800), or Chapter 3 (commencing with Section 29900) of Division 9 of Title 4 of this part, or Section 8100 or 8103 of the Welfare and Institutions Code, from possessing firearms or ammunition who obtains title to these items by bequest or intestate succession may retain title for not more than one year, but actual possession of these items at any time is punishable under Chapter 1 (commencing with Section 29610), Chapter 2 (commencing with Section 29800), or Chapter 3 (commencing with Section 29900) of Division 9 of Title 4 of this part, or Section 8100 or 8103 of the Welfare and Institutions Code.  Within the year, the person shall transfer title to the firearms or ammunition by sale, gift, or other disposition.  Any person who violates this section is in violation of the applicable provision listed in Section 16590.