Surely, we can come up with reasonable limits on the right to keep and bear arms. To impose these restrictions correctly and legitimately, we would need to enact a Twenty-Eighth Amendment that fleshes out the Second. Perhaps we could limit the right to keep and bear arms to those weapons with destructive power equivalent to the best heavy weapons of the late Eighteenth or early Nineteenth Centuries. This would permit citizens to arm themselves, but not with weapons so capable of killing vast numbers of other people that the risk would outweigh the benefit. This framework might draw the outer boundary at, say, a mid-size howitzer, a backpack sized flamethrower, a shoulder-launched surface-to-air missile, or an anti-tank mine. Such weapons are destructive, to be sure, yet still comparable to the power wielded by a militiaman of two hundred years ago, standing behind an artillery piece or on the bridge of a privateer’s ship, firing at a crowded enemy troop vessel. Therefore, these weapons should be suitable for private ownership.
So, in conclusion, every US citizen should be allowed to buy one of these, if s/he can afford it. I'm sure I can't imagine why the American right is a universal target of mockery.
(HT Primly Stable on Twitter)