Don't think this is anything other than mercantile propaganda from the manufacturers and their lobbyists. Remember, these are low-information purchasers who listen to the likes of Limbaugh - himself a recipient of the lobby's largesse.
Nailed it.
It's the reason why right-wing media exists: To scare the crap of their audience and make bank while doing so.
My 50 cals are getting harder and harder to find...along with ammo for my ground to air missiles.
But .22's are abundant at local sporting good stores. So are .357's. But I admit, the price has gone up a bit.