Grenades are like RAM, you can never have too much
Posted by: FunkSoulBrother
basically like Fatal Factor said - if you jump onto youtube and search 'silenced machine gun' you'll find that you can't really quiet down an SMG that much.
but, thanks to the silencer, you get better range/accuracy, so you can actually zoom in with it and fire. and also (most importantly), it absolutely SHREDS the buggers. i dunno about you, but the drones have been such a pain for me in Halo 2 & 3, so the silenced SMG easily became a favorite of mine since the drones are no match for it.
If you fire caseless ammunition with a suppressor, the gas has no where to go but the suppressor, It would barely make a whisper.
Bungie was lazy when it came to coding them, that simple.