All the BGs will just use revolvers...
Yeah, that'll be helpful. Instead of having victims shot with 9's that they might survive, we'll have victims being gunned down with .44 magnums.
No they won't. They will use guns made before 2008. Besides its a California law, gun makers won't bother making auto loading handguns guns just for California. After 2008 if this law stands, you'll have to buy used autoloading handguns.