Preemption
California law (53071 GC) restricts county and city authorities from enacting firearm regulations. This provides for uniform firearm laws and prevents situations found in other states (such as New York) where traveling with an otherwise legal firearm could put a citizen at risk of violating local city ordinances.
Because of their inability to regulate firearms directly some cities, such as Los Angeles, have enacted ammunition regulations.
Read more about this topic: Gun Laws In California