You're nuts, dude. Citizen militias are not the same as the government-funded military. The US government owns all of those weapons the military uses, and they are "registered" with the US government and that branch of the military.
But citizen militias are not part of the US military, even though they could conceivably be used in the defense of this country in an emergency. And they use their own personal firearms, which are not "registered" by the US government or the military.
Personally, if the shit hit the fan, I'm picking up whatever government hardware I could find on the ground, and using it, which would do a much better job of killing invaders than the weapons I own.