As nearly as I can tell, the Ninth Circuit Court has decided that California can legally impose "broad" restrictions on "acceptable" firearms.
(NOTE: the following two paragraphs are ALL "Copy & Paste" quotes; see the links for details. I haven't yet had the time to drill-down to the logic of either the order or the interpretation by a 3rd party blogger. I offer minimal interpretation or commentary at this time. Some phrases are high-lighted for your attention, not because they are embedded in the original text.)
GUN WATCH: Ninth Circuit Panel Rules CA Unsafe Handgun Act not Covered by Second Amendment: The key to the decision is the Ninth Circuit's hostility to a broad reading of the Second Amendment. The Circuit, in it's en banc rulings, such as Peruta, Tiexeira v. County of Alameda, and in a three judge panel, Silvester v. Harris, has consistently worked to restrict Second Amendment rights to the narrowest possible box.
An analogous reading of the First Amendment would be that the State can restrict certain publications on the grounds that they might impact public safety. For example, that violent video games could be banned. The Supreme Court has rejected that argument for the First Amendment.
The upshot is that California can impose restrictions on "Acceptable Handgun Characteristics"; some of which may make it more difficult for handgun manufacturer to keep handgun prices affordable; others which may be technologically unfeasible, and finally most or all of these new regulations may require mandatory registration (in case nobody noticed the nuances of the legislation).
Here is the summation of the opinion of the court, From Pena v. Lindley:
California requires that new models of handguns meet certain criteria, and be listed on a handgun roster, before they may be offered for sale in the state. Two provisions require that a handgun have a chamber load indicator and a magazine detachment mechanism, both of which are designed to limit accidental firearm discharges. The third provision, adopted to aid law enforcement, requires new handguns to stamp microscopically the handgun’s make, model, and serial number onto each fired shell casing. Plaintiffs asserted that these three provisions have narrowed their ability to buy firearms in California, in violation of the Second Amendment, and that the handgun roster scheme imposes irrational exceptions, in violation of the Equal Protection Clause of the Fourteenth Amendment.
Note that some of the provisions eliminate category your standard 1911 frame; others (microstamping) require technology which has not yet proven feasible by current production technology.
(1) it's convenient, as a state, to be able to require technical tweaks which are not yet possible for the manufacturers to conform if you want to make it more cumbersome (impossible) to own a new firearm:
(2) I'm glad I don't live in California