The issue with gun registration is that one day thr government may become oppressive and make guns illegal and thrn those registrations can be used by an oppessive govt.
The other issue is profiling. Cops might use registrations to target people as suspected and as such owning a gun, even if you never use it, makes you a target of wrongful arrest.
We already have a "one-way" system that is essentially a registrstion. As long as you have a gun or its serial number you can track it back to who owned it, but not the other way around. Assuming it is all legal of course.