I love assault commando. I can take most classes 1v1.... notable exceptions are probably sentinels (very good ones) and shadows (especially when they charge in at speed and force shroud through my AP opening).
Gunslingers? Piece of cake on most maps. They are turrets that flash warning lights at me when I need to break LOS. I duck out of LOS and kill them at ease, usually with little damage taken. (Sometimes they get desperate enough to throw orbital strike at me.... makes me LOL when that happens).
What's your build and rotation?
I have to admit I have doubts.