After reading the Bad Elk Supreme Court decision, I think this wording is questionable at best.
The Bad Elk decision means that if the government tries to confiscate your AR-15/AK-47, or arrest you for having one, you can kill the offenders on the spot, even if they are not trying to kill you.
What the court found was that the defendant had the right to resist an illegal arrest with whatever force was necessary to prevent the arrest. So rather than saying "you can kill the offenders, even if they are not trying to kill you, I think a more accurate description would be that you have the right to resist an illegal arrest with whatever force is necessary to prevent the arrest. IOW, the normal rules of self defense apply. If the officer comes to effect an arrest, you refuse and he says, "We'll be back" you can't shoot him in the back as he's leaving. If the officer draws his weapon and insists that you will be coming with him, you would have the right to draw, and to fire if you felt he was going to shoot you.
It's important to note that when the officers came to arrest Bad Elk he had broken no law and there was no warrant for his arrest. Resisting officers who came to confiscate your weapons with warrants in hand, while clearly unconstitutional, would not be the same fact pattern as the Bad Elk case, and you would have serious problems defending your actions in courts which would clearly recognize the unconstitutional law as legitimate.
If they have a warrant to take you or your guns then Bad Elk would not apply. IANAL and IDNSIAHILN
