As I understand the thing, federal, not California law, U.S.S. Dianne Feinstein had proposed another of her amendments, this one to the Senate Juvenile Justice Bill, which was adopted and sent to the House. Her latest effort would ban the import of large capacity magazines and or "feeding devices" larger than 10 rounds. Additionally it would CRIMINALIZE possession of any already owned. These is NO provision for "grandfathering" any existing items. As the lady said, respecting The Feinstein Amemdment to 1994 Crime Bill, her goal was/is to totally ban ALL firearms, her phrase was "turn them all in". As the interested reader can readily see, nothing much has changed. Ten round magazines today, no round magazines in the not to distant future.
By the way, respecting House action, what they actually passed, their version of Juvenile Justice STILL carries this latest Feinstein Amendment.
Alan