My understanding of the laws is that if your brother is a resident of California that this would be illegal. It would circumvent the required background check for ammo, and I also believe it’s illegal to bring in ammo from out of state (e.g. you travel out of state to hunt, buy a box of ammo and return to Ca with unspent rounds....you have just committed a crime under our laws). Again, this is my understanding. Not an expert. I handload now so all good until they make that illegal too.