See the NFA Act. Each grenade is legally a separate destructive device. Some States outlaw destructive devices, but they are legal under Federal law (with appr

See the NFA Act. 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.