> Grenade ownership is fully legal in many or most US states
Do you have a source to back that up? I think you can own a grenade launcher, but I'm quite certain that grenades are very illegal... possibly excepting smoke grenades.
Each grenade is legally a separate destructive device. Some States outlaw destructive devices, but they are legal under Federal law (with appropriate permits).
You don't see people with them because there are not many transferable grenades left in circulation. If you want to shoot a bunch out of a m203 launcher it's cheaper to go to Cambodia than exhaust US civilian stocks.
Do you have a source to back that up? I think you can own a grenade launcher, but I'm quite certain that grenades are very illegal... possibly excepting smoke grenades.