THE DAILY FUDD: E83: "A Tale of Three Fudds, Part 1: The arms."

The Supreme Court can

Three permutations possible from a baseline 2A interpretation:

KEEP: The original 1688/89 English Bill of Rights "blunderbuss," modern style.
BEAR: Handgun, added in American experience.

LOW: Manual action: Shotgun and CCW.

MIDDLE: Pistol-caliber with higher-than-ten-round magazines.

HIGH: Featureless military-grade rifles (expanded from blunderbusses by American experience) with 10-round magazines; 20-round magazines for pistol-caliber arms.