[Logical me]

All federal gun laws are unconstitutional and any restriction is up to States. Even so the State cannot disobey the Constitution therefore the States have to be very careful not to prohibit my ownership of a gun. Even gun registration is illegal since it is an evasion of privacy.

[coloradan]

It's not up to the states. Note that the First Amendment says "Congress shall make no law ... " which leaves the doors open for states and municipalities to ban books, religions or free exercise thereof, etc., while the Second Amendment says, flatly and without exception, "the right of the people ... shall not be infringed." The latter doesn't only constrain Congress, it constrains all legislative bodies.