I don't think the recent ruling mentioned "assault weapons". I believe it was regarding "semi-automatic rifles".
Even people 21 or over can't buy "assault weapons" in California. It's far too dangerous for people to keep and bear arms that have pistol grips on them. Or those very lethal flash suppressors. And don't even get me started on the evils of having an adjustable stock.
Don’t forget “that shoulder thing that goes up”