None, actually. In some states it is illegal to import magazines into. One state cannot make an action illegal outside that state. For example, California cannot prosecute a Nevada resident for shipping a high capacity magazine into California from Nevada because California laws cannot reach into Nevada to make an action taken by a Nevada resident illegal in Nevada.
Now....one state could negotiate with another state for extradition if they can convince the second state that someone in the second state was part of a conspiracy with someone in the first state. So, California might convince Nevada to extradite a Nevada resident to California for conspiring with a California resident to knowingly enable the California resident to violate California law - only if Nevada agrees.
