Hillbillydeluxe

I want to know how I can buy ammo for my antique firearms in California, I have legal reg. Guns and also some that were not required to be registered here and still don't see any laws requiring me to register them but with the new ammo law, I don't have any gun registered in some of the antique caliber long guns I have, I reload so it's not a huge problem but I like to buy some ammo because it is cheaper to buy factory ammo than to buy dies and brass for a rifle I barely use