This is the best they can do?
California proposes requiring barrels to be microstamped, or should I say microstampers, so as to engrave their gun's serial number on a bullet.
California Brady Campaign "strongly" endorses it. While acknowledging it may not lead to catching a criminal shooter, who "could have gotten that gun illegally," but "if we can go back to the original purchaser or the original dealer of that gun then we can stop some further trafficking of guns to prohibited purchasers."
So in most cases, they'll be able to find the dealer who sold to the person from whom it was stolen. That will be valuable, I'm sure.