Is the shotgun the best HD in California?

I'm two seconds away from going to put a down payment on a back ordered Mossberg 940 Tactical.

I have Glocks, M&P pistols, Mag locked AR, but I feel like I need something for HD if shit hit the fan.

All my pistols are CA compliant. 10 round mags. My AR is mag locked and 10 round mags also. If I jam or double feed, I'm dead.

Is it the best we're gonna get in CA? I would have semi auto, with 8+1 with an 18inch barrel. Pretty similar to my AR but with incredible stopping power and easy operation.

What do you guys think?