Guess it’s just being safe

It may be referred to as "pistol-caliber", but the round doesn't define the weapon class.

i read it as “does NOT include” at first glance, which is my mistake. but that makes it even more confusing; when the hell has 7.62 and .223 EVER been pistol ammo? i get AR “pistols” and mini AKs like the Draco, but it’s essentially a rifle caliber. that basically leaves shotgun ammo and less-common calibers like .30-30.

That's the point. The rules are being made by people who've never played the game.

ahhhhh gotcha.