From the Canadian gun-controller/banner organization (pdf link):
Q — Will registration lead to confiscation?
Gun control is not gun abolition and claims that it will lead to confiscation are not based in fact. In the vast majority of cases where specific types of firearms were prohibited because they were not deemed appropriate for hunting or target shooting, the owners were grand-fathered. This enabled them to keep those guns until their death and in the case of short-barrelled handguns, owners became a restricted class and were allowed to trade amongst themselves.
But that is exactly what is happening to our neighbors to the north. Registered guns are being confiscated because some pencil pusher decided that some of them looked scary.
Learn from the Canadians. Resist any gun registration scheme, regardless of how cheap, easy, or "common sense" the controllers/banners make it sound. Don't listen to their empty promises to not take anyone's guns. Gun registries are simply too easy and tempting to abuse and if you give them one, that's exactly what they will do.