Exactly how smart do you think your average criminal is? If they are committing crimes in the first place, they probably aren't too bright.
Maybe you gun nutters could come up with real solutions and pugs for those solutions instead of always complaining when the anti gun folks come up with their own solutions.
They're bright enough to not use their own legally-purchased guns, rendering microstamping useless. Most crime guns are acquired through straw purchases, and most of the rest are stolen.
Violent crime has been declining for two decades. There is no need for yet another expensive, ineffective feel-good law to "solve" a problem that's already being controlled, particularly when it will significantly impact law-abiding citizens by increasing prices and reducing (or completely eliminating) selection. A stupid solution is worse than no solution, and something that can be defeated dozens of ways with little or no effort is pretty stupid.
Do you genuinely believe that this will reduce crime, or is it just that you enjoy seeing the "other side" get screwed?