Last Updated 2/23/2019
For California residents, handguns must pass a 'drop test' to legally ship and/or transfer in the state of California.
If the buyer happens to be California Law Enforcement, there is an exception and the buyer will need to provide proper documentation on authorized letterhead.
Regardless, you or the buyer will need to contact the Receiving FFL to confirm the item and the magazine are legal to ship, and be owned in the state of California.
Visit the CA DOJ Certification List page.