What if instead of a gun-owner-registry, there were a national gun-registry?

[NutmegYankee]

83. That's because all land is purchased in a legal deed concept called "Fee Simple".

In English law, a fee simple or fee simple absolute is an estate in land, a form of freehold ownership. It is the way that real estate is owned in common law countries, and is the highest ownership interest possible that can be had in real property. Allodial title is reserved to governments under a civil law structure. Fee simple ownership represents an ownership interest in real property, though it is limited by government powers of taxation, compulsory purchase, police power, and escheat, and it could also be limited further by certain encumbrances or conditions in the deed, such as, for example, a condition that required the land to be used as a public park, with a reversion interest in the grantor if the condition fails; this is a fee simple conditional.[1]

https://en.wikipedia.org/wiki/Fee_simple

Police and search rights are limited further in the United States by the 4th Amendment.