[kQq9oHeAz6wLLS]

It'll never happen. As op said, it's laughably trivial to remove, and thus criminals will remove it.

Legitimate gun users will, at best, use their weapon in self defense, in which case they'll be sitting there waiting when the police arrive, so no need for microstamping.

The "crime of passion" so popular in TV shows are few and far between, and there's usually a huge amount of other evidence.

[knorker]

I think you're overestimating the intelligence of most criminals. And their gun logistics discipline.

If it were possible to do, it'd help.

Also, removing the marking mechanism would be a process crime. Process crimes are very useful for catching criminals.

Are you against serial numbers on guns too? You can always file those down.