That sounds complex. Just put some gunpowder at the rear end of the grenade, and stuff it in a small tube.
You could make this small enough to stuff the tube under the barrel of your gun, or big enough that it can function as a small artillery piece.
You could even give it some sort of rocket propulsion.
That sounds complex. Just put some gunpowder at the rear end of the grenade, and stuff it in a small tube. You could make this small enough to stuff the tube under the barrel of your gun, or big enough that it can function as a small artillery piece.