Section 30530 Of Article 1. General Provisions From California Penal Code >> Division 10. >> Title 4. >> Part 6. >> Chapter 2. >> Article 1.

. (a) As used in this part, ".50 BMG rifle" means a center fire rifle that can fire a .50 BMG cartridge and is not already an assault weapon or a machinegun.
  (b) A ".50 BMG rifle" does not include any antique firearm, nor any curio or relic as defined in Section 478.11 of Title 27 of the Code of Federal Regulations.