My Constitution would definitely include a fundamental human right not to get shot.
Everyone would be allowed to own as many guns as they liked, but every gun would have to be fitted with an undo button -- which would have to be tested regularly, by having one of Her Majesty's Inspectors of Firearms shoot the gun's owner and then undo the shooting. If there was any probability of an incomplete reversal, then to ensure that as much as possible of the damage can be undone before the undo sequence fails, the Order of Restoration would have to be: humans (except the gun's owner), animals, plants, inanimate objects, the bullet, the gun, its owner.
I don't see how anybody could possibly disagree with that. It's the fairest system Sad, socially-inadequate men with shallow lives would still be able to have their rocking-horse cowboy fantasies to let them feel a little less pathetic; but if anybody ever accidentally got killed or maimed, the damage could easily be reversed. Hunters would be allowed to shoot defenceless animals for their own entertainment, even endangered species, as long as they restored them to life afterwards. And as a protection against suicide, guns could be designed automatically to undo after a predetermined interval unless a "stay shot" button was pressed before the timeout expired -- so if you were already dead, you would be unable to prevent yourself from being automatically revived.