Don't bring it to CA. Not legal here.
I used to have a .410 that was highly illegal in NY. It began its life as a breakaway single barrel, but I cut it down to just a few inches longer than the chamber. Then I cut the stock off except for a pistol grip. It was mean and scary looking, and with 3" slugs the freaking thing kicked like a mule. Wish I still had it, but got broke and sold it to a buddy for $100.