I may be among the ill-informed, then. Or maybe I'm just confusing "registration" with "trackability". But when I buy a gun at a gun store, isn't my name then associated with that gun in the dealer's bound book? I agree that's not the same thing as a statewide or nationwide "registration", but it does connect the gun to me, so I can see how someone might want to acquire a gun via a face-to-face private transaction in order to avoid any formal record of ownership.
It does, but it isn't registered to you, which means the government can find out that you bought it perhaps, but not whether you actually still have it, which is a big difference.