Medic - meds are the best counter to sniper. There speed keeps snipers from running to far away once you know where the sniper is, and it is a little harder to hit them from 500 - 600 meters out. You can try doing the snipe and move, but once i know where the area is that your sniping from your done.
Granted if your 900 meters out i cant see you or here you. But there is no where on stock maps i cant get to you execpt hornets nest and double barrel.
__________________
|