This morning on Fox News:

WALLACE: What about… a weapon that can fire a hundred shots in a minute?
SCALIA: We’ll see. Obviously the Amendment does not apply to arms that cannot be hand-carried — it’s to keep and “bear,” so it doesn’t apply to cannons — but I suppose here are hand-held rocket launchers that can bring down airplanes, that will have to be decided.
WALLACE: How do you decide that if you’re a textualist?
SCALIA: Very carefully.