More or less. It basically goes Federal > state > county > city > my household. (Two rules: 1. Pick up after yourself, and 2. If you're done with it, turn it off. ) If no specific law has been made restricting something federally, then states can add restrictions, and then counties, and so on down the line, unless a higher authority has a law in place saying something to the effect of "...shall pass no law restricting/allowing (whichever of the two the case may be) blah blah blah..." So, like, all these states passing laws allowing recreational weed, for example, TECHNICALLY are trying to supercede federal law, where marijuana is still a no-no, but the Feds have all kinda taken a stance of "we're just gonna sit back and let it happen and watch n' see how it plays out." As far as that front goes, it's more an issue of when and not if it gets taken off the list of federal controlled substances, or at least reclassified. (Currently, marijuana is classified as being more dangerous than cocaine - go figure. )
Far as gun laws go, it's sorta like things are on the opposite path. Where weed laws are getting more and more loose, gun laws over the decades have been gradually constricting. Sure, concealed carry laws on a state-by-state basis have been opening up over the years, and the DC vs Heller SCOTUS ruling did a LOT for gun rights, but beyond that, things have been incrementally getting worse over the years. And, without getting too much into politics, I fear things are about to get a whole lot worse soon over the next couple of years. All we need is one more nutjob to do another mass shooting that the media will sensationalize to death, and that'll get the ball rolling for sure - only thing preventing that is COVID-related restrictions preventing people from gathering in large numbers. (Notice we haven't had one since this Corona lockdown crap started?) Guaranteed, the usual folks are already sitting in their offices with bills typed up and ready to introduce, just looking for a juicy tragedy to exploit.
Anyway. That's the gist of it. Feds are supposed to just lay the basic framework, then states can add further specifics that apply to their regions, and then counties tailor things to their more localized areas, then cities, and so on. Alas, there are soooooooooo many thousands of laws on the books on the federal level, it's sometimes hard not for states to pass legislation that conflicts with it, whether by design or not. And when states try to buck the system and say, "Nuh-uh! We gonna do what we want!" then it usually doesn't play out well in the SCOTUS ... like Arizona's SB1070, for example. Lotta states (AZ included) have passed laws on the state level saying, "We prohibit the enforcement of any gun laws more restrictive than what we already have on the state level," and some counties likewise saying the same with regard to state laws. They're mostly symbolic gestures, as they don't/won't hold up in Supreme Courts because federal law overrules state law, and state law overrules county-level.
Sorry for the tangent. Too much caffeine again. As usual.
A. Beginning October 1, 2010, a personal firearm, a firearm accessory or ammunition that is manufactured commercially or privately in this state and that remains within the borders of this state is not subject to federal law or federal regulation, including registration, under the authority of Congress to regulate interstate commerce and is not considered to have traveled in interstate commerce.
B. This section applies to a firearm, a firearm accessory or ammunition that is manufactured in this state from basic materials and that can be manufactured without the inclusion of any significant parts imported from another state.
Sounds to me like that applies almost exclusively to 80% lowers. The part about "basic materials ... manufactured without the inclusion of any significant parts imported from another state" kinda eliminates just about everything else. Unless, of course, you're Ruger...
Speaking of Ruger, that kinda makes me wonder ... could they then technically manufacture whatever they want as "Arizona resident exclusive" firearms? Stuff produced solely for purchase/use by Arizona residents ONLY? Given, they'd never actually do it because there's not enough money in it for them, but still...?
Anyway, again, I don't think it's something that would ever really stand up in federal court under SCOTUS review because of that whole federal > state > county > city thing. The feds already have like 10k gun laws on the books, and the ATF loooooooves to interpret those things however they see fit based upon whatever random whim they fancy (depending upon which way the political winds are blowing at the time, it seems). So, if it ever came to pass that someone was arrested/charged/convicted of a firearm violation and tried to cite that law as a defense, I seriously doubt it would hold up in the long run. It would likely get struck down by the 9th Superior Court (since they generally don't favor gun rights, historically), and then SCOTUS would just refuse to hear the case, and that would be that. Just my guess.