All this might have a real chance if the registration of firearms hadn't been so universally and systematically abused in Australia, Britain, and Canada by those who ended up forcing the program to confiscation. If there were an iron-clad, enforceable guarantee that such a registration would never be so abused the NRA wouldn't get the traction it does. In fact, mendacity on this issue on the part of gun controllers in other countries has pretty much thwarted their counterparts' efforts in the U.S., and I'm hoping it will continue to do so.
As an aside, I have to laugh at this idea of the imprinted serial number. I do a lot of reloading and pick up empty brass from many sources, including law enforcement ranges. (They don't use anything but factory for obvious reasons). After awhile, the cases I fire would have so many serial numbers on them that they would look like they'd been roughed up with sand paper! Then just multiply that by the thousands and the whole idea is just so much gibberish.
Not that I approve of the scheme, but that wouldn't need to be the case. Just as a gun recovered at a crime scene can be traced today, the gun could be traced the same way from the ID mark on the case. How? They go to the manufacturer who tells them what wholesaler the gun was shipped to, the wholesaler then tells them what dealer was shipped the gun. The dealer consults the "yellow sheet", and finds who bought the gun from him. That won't be the criminal in all but the most trivial cases, such as domestic murders. These scemes are more useful for getting evidence for the trial than it is in finding the perp in the first place. They do nothing whatsoever to stop the crime from being commited, nor do they protect any of the would be victims.