As for microstamping, the biggest problem I have is, assuming it was cheap, viable and reliable, how it could be used to prosecute criminals. With my limited legal knowledge, I would think that the ability to match a casing to a gun, and a gun to an owner, does little to say who shot the gun and could only be useful as part of a larger case. Its not an end all to stopping criminals, and therefore is certainly not the technology that would catapult forensics from the stone age to the future. And if the statistics regarding canada's gun registration are any indication, then it was wise of NYC to vote out such a law.