RPG comes from
Ручной Противотанковый Гранатомёт
Meaning handheld, antitank, grenade launcher.
An M203 or an mk19 is a grenade launcher. An AT-4 or RPG-7 is a rocket or missile launcher, firing a warhead.
Do you see what I mean?
A grenade is a fragmentation device. And yes these are technically grenade launchers, but they're specifically anti-armor, rocket or missile launchers.
Which Nashville shooting?