There are only two levels of sovereignty in the United States: Federal, and State. Counties and cities are political subdivisions within, and legally a part of, the State. The power that is exercised by these entities is delegated State power.
(I am not an attorney, but am familiar with this issue as it exists in the law of California.)
what is the last word of the tenth amendment?
"people". The problem is that that last word has no effect unless the State constitution gives it an effect. The California Constitution, for example, has no analogous provision.
https://leginfo.legislature.ca.gov/faces/codesTOCSelected.xhtml?tocCode=CONS&tocTitle=+California+Constitution+-+CONS
I have no doubt about california.
because...
Guns...
not just for hunting.