Some autos cannot be sold in CA, due to various regulations. No logical reasons, but safety is cited.
So some autos are ‘converted’ to single shot, and then sold in CA. State DOJ agrees with the process. Then the owner can modify his single shot into an auto.
For example, Model 1911s, designed as originally by John Browning cannot be sold in CA because of no loaded chamber indicator.
There's a bunch of good, safe weapons that are not on the list. Major brands.
But you can buy one from a friend or family in another state and import it.
Still have to "register".
Generally you want about 1/2 your guns around here to be registered.
That way you have some you can use during normal times to shoot home invaders and zombies, and a whole 'nuther set for TEOTWAWKI.
Living here I can tell you nobody is following the law to a 'T'.
Millions of felons as far as the eye can see.