did you own the mag before the CA ban on hicaps? In that case its absolutely ok.
You can not buy sell or trade hicaps nor can you import or manufacture your own hicaps(by manufacture i mean put ur rebuild kits together) in CA no matter of when they were manufactured.. that would be a crime.
What isnt currently a crime is simple possession of hicaps.... If you some how stumbled across a hicap on the ground and picked it up it is not technically illegal. Although you will have fun with LEO playing that card. Expect a serious hassle.
All of this is as of this moment.
NRA-ILA | California: Anti-Gun Bills Scheduled for Committee Hearings Next Week
396 is to address this. 374 is gonna make ur mini a bad guy. and 47 will kill the bullet button on the evil feature ARs
Check out Calguns.net for CA specific info.. I read alot over there but pretty much only post over here.. i like the people here better