The legislation is not to engrave bullets, but to require "micro-engraving" on Firing Pins of semi-auto, so when the firing pin hits the primer, it would leave a microscopic engraving of the guns maker, serial, etc. on the spent case. This data would be kept on a database, and supposedly be able to track back to the owner.
This would apply to semi-autos only, since revolvers do not leave the shell casings behind in the scene of a crime.
Of course this would be of no use if the "criminal" changes the firing pin, or just slightly file down the end of the pin. Who is to say a criminal won't plant another's shell casing at the scene
This is just another stupid C**P idea, all in CA's attempt to eliminate handguns all togeather.
Since they can't succeed in an out-right ban, they will raise enough legislation that gun manufactures will just stop selling there.