Problem with penetration is lasers and muon's. Realistically there's very little that can stop them, so if I fire my "Laser" and spin 360 degrees?
"GODLIKE!"
Military Surgeons have often said there are three possible effects of being hit by a bullet.
1) Instant Death.
2) Serious Rupture that shuts down the body within seconds.
3) Negligible Effect.
And realistically, if you fired an RPG in a room, you're dead as well from either the front or the back blast.