Add one more facet to the threat
Besides taxes and serial numbering of ammo, remember the single most dangerous potential threat, the computer.
Yes, that's right, the computer. Not especially the one you are reading this on, but the one in your gun! "Smart" guns are potentially the worst threat we face in the long run, because of how "safe" and "reasonable" they could be.
How can you object to a gun that only fires for it's legal designated owner? Think of how much safer we would all be, with no accidental shootings by children finding a gun, or taking a gun to school? No more shootings by criminals, gang members, etc. All this and more is in the promise of the smart gun. It might even be able to use biometric feedback to determine the owners state of mind and disable itself so it would prevent a suicide! Think how we would ALL be so much better off!
Once smart gun technology "prooves" itself, there will be a huge rush to ban all non-smart guns, since they are not safe enough. ALL of them, rifles, pistols, shotguns, all will have to be turned in, but hey, you can replace them with smart versions, so you can still hunt, and protect your family. Smart guns could even prevent violations of game laws, like hunting out of season, or before/after shooting hours, or (with a GPS) prevent hunting in prohibited areas, etc.
The Government might just not require us to turn in our "dumb" guns, they could even go so far as to assist us with their replacement with smart guns, vouchers, tax credits, etc. There are lots of things they could do, and do under current law to make that happen.
Any potential flaws in the idea will be ignored, or steamrollered into nothingness in our transition to a truly safe society. Little things like the smart guns not working when needed, or criminals defeating the lockout technology (and it will certainly be a crime to do so), and of course, the one feature that anyone mentioning it will be considered a loon, the feature that could be built in, a LEO override. Think how many lives will be saved if the cops (local, state, and Fed) could disable a gun at a distance! They won't need to confiscate any guns after a hurricane, they'll just broadcast the signal that turns them all off! Think of all the trouble that will save!
There are lots of possibilities, and we are on the edge of practicality for some of them. Don't scoff, some gun company might even lead the way, because, after all, they are not in business to protect us, or our rights, they are in business to make money.
Other countries needed worry too much, as they have already banned most guns. In fact, it might even be that smart guns would be allowed, even popular in places like Britain, Australia, maybe even Europe. I mean, hey, a gun that could not be misused? One that would only fire with Govt permission? How could they object to that?
The smart gun is the edge of a tremendous slippery slope to Hell, and while we are not sliding on it yet, you can see it from here. Be aware.