I recently relocated to California and can shed some light on this topic. I own many S&W's that are NOT on the approved California list. If you are already a resident of CA., and you now want to bring in a handgun, it must be on the CA approved list (Check DOJ Website). If it's not on the list, you cannot bring it in via FFL dealer (none will stick their neck out for you).
The only other way is if you can take "legal" delivery of a handgun (not on CA approved list) in another stated, as in y case, my orignial home town, then you, as a private citizen, already owning it, can bring it in to CA. You are however, required to "voluntarily " register the handgun in CA. I still maintain duel residency in two states.