You aren't getting the guns out of the hands of the US. You could get some, but people will cling to their guns like they are their children.
You talk like gun owners have some sort of favorite son scenario with their firearms. As if the less treasured weapons that didn't get passed down from gramps or aren't the favored modern home defense mechanism just get left lying around for someone to shoot up a school with. You even call them Sandy Hook guns and claim you only want to forcibly take away all those extra guns everyone has just lying around the house.
As a gun owner myself, I know this to be a fact, actually. There are weapons in my home and in my friends' homes that get treated MUCH better than the others. They are simply more highly valued, either monetarily or for sentimental reasons. This is just how people work. The new/valuable/vintage car gets parked in the garage, and the commuter car gets parked in the driveway or on the street. The new couch goes in the living room, and the old couch gets moved to the rec room for the kids to jump on. There are Dad's Tools which you don't touch, and the other tools that anyone can use. The analogy works for guns as well. There are some guns that are treasured, locked up properly, cleaned regularly, etc, and then there is the old pistol that's in that box out in the garage, or whatever. And that is where the Sandy Hook shooter got their weapon... from his home, where his Mom had them improperly secured. You seem to be quite in a lather over many things I actually did not say. In fact, my whole post - the point of the whole things, and stated multiples times within the post itself - is to inquire about what INCENTIVE would appeal to gun owners, to get them to release their less-cherished weapons? I never said anything about force at all. I suggest that some self-examination of your motives and prejudices might bring some valuable insights.