Good amount of thought put into balance, doesn't carry my usual distain that comes with seeing an LMG thread. The weaknesses are well thought out, and when you put it all together (contrary to the point I so vermently argued in a certain other thread) it seems like it could work.
My only real concern is how it alters the style of its given perk. I feel its definately a Commando weapon if anything, since I recently learned it fires the same kind of rounds as the other Commando weapons. Also the Commando does overcome alot of the immediate downsides to the weapon, so it seems quite desirable for the Commando.
Plus Support is meant to be poor at long range, and even with the lack of iron sights, this weapon would still perform pretty well at range. Then of course they already have the AA12, and lets face it Bren Gun + AA12 = rape.
Plus alot of players see the Support as the new Sharpshooter, we don't need to fan that flame anymore
My issue is, what would the Commando buy this for? This weapon would have a big clip (including perk bonus) pushing it closer to that turret weapon people fear, and a big damage output, a quick reload (Due to Commando's fast reload bonus) and low recoil (Perk bonus). This would shift the Commando from his designed role of taking out smaller foes and focus him onto taking on much larger foes.
My fear is at worst it would either become the new M14 unless its ammo were rather stingy or it creates largely the same problem the SCAR did before the nerf, where rather than do their job Commandos went after everything.
Not saying No, but I'm not saying Yes either
EDIT: On a side note, its definately not a Medic weapon. Medics have no place holding a such a high powered weapons with such a big ammo supply. Don't forget that the Medic gets double the clip size for his weapons so he owuld have the huge 100 bullet turret that everyone fears this gun will become. They have it in BFBC2 because they shrank the 9 classes down to 4 so their perk descriptions are rather broad. Killing Floor has 7 perks. Medics job is to heal and take on small enemies in a pinch, nothing more.