In Wisconsin, a machine gun is defined as a gun that will fire more then two rounds with the single pull of the trigger. Does this mean one could use select fire components modified to obtain a "two round burst"? or do the federal laws on the select fire components overide state regulations? If so would it still be illegal to modify non select fire components to obtain the "two round burst"? Gunnut.

No - unless they directly contradict each other, the more restrictive law applies.  In this case, that's the federal definition of a machinegun.