OT: i don't think that's possible.
wait whatwhy can't impact grenades be made? i'm pretty sure there are some already out there
Im pretty sure that back around the days of maps, there was a weapon pack that was released which included literal impact grenades that explode when they hit something (Im not sure if this is what OP wants) and a launcher for said grenadesi forgot the name of the pack though
Uh i was referring to dodgeball with grenades.