The gunsmith/FFL says it's legal and I can't find anything on the DOJ site that says different. It's a sporting shotgun without any of the "evil" features like a removable mag, pistolgrip or folding stock, bayonet lug, flash hider, etc...
Cali restricts mags to ten rounds and it even complies with that.
“If ye love wealth better than liberty, the tranquility of servitude better than the animating contest of freedom, go home from us in peace. We ask not your counsels or arms. Crouch down and lick the hands which feed you. May your chains set lightly upon you, and may posterity forget that ye were our countrymen.” ― Samuel Adams