I've done this in BFBC2. I currently run around as a sniper using a pistol as my primary while everyone else runs around with the best LMGs, assault rifles and sub-machine guns.
I love doing abstract and odd things in BC2.
My favourite sniper killing tool is stationary launchers.
I also like to snipe in the game, theres the extra depth to it with bullet drop. Getting into a sniper battle with another guy across the map is actually fun.
Even though some people hate it, I occasionally will get a tank with quick reload or the long range upgrade and perch myself on a hill providing artillery cover on a CP. Tanks also make fantastic anti-aircraft weapons.