From a legal standpoint, has any limit been placed on the second ammendment? could someone/has someone sued on the claim they should have access to WMDs?

There is a distinction between a “device” and an “arm”. This is why there is no constitutional right to own a WMD like a nuclear bomb or chemical bomb. Rocket launchers are considered “destructive devices” and you can buy those as well as the munition for it. Good luck getting one though.

However, if you go through proper channels it’s amazing what you’re allowed to own. In some states you can not only own a tank (that’s the easy part - you can even import one if the guns are disabled) but could also have it stay equipped with its standard issue .50cal gun! You won’t be allowed to drive it on public roads though. They are also cost prohibitive.

Hell, you can buy fighter jet if you’d like. But it has to be demilitarized which although still fun to fly would sort of limit your ability to maintain air superiority against a properly provisioned force.

Chemical, biological, nuclear, and anti-aircraft weapons are off-limits according to federal law. These rules have been enforced against people with terrorist intentions, but I would imagine any private citizen who believes they should be able to have them and can actually acquire them doesn't really feel the need to bother with fighting the law so long as they don't use them.