Mine is somewhere around 14% i think, I'm not too sure nor do I really care about head shots, but today I was getting alot of headshots, I used the K2 with an itec sight and an S1, with a stock PSG-1. I let the recoil go and I got most likely around 15 to 20 headshots in one game at two towers. No body said anything because I only had 30 kills with 12 deaths and I was twice everyone's rank, but it was great just to pwn a bit and get my hs percent up. Try my gun and mods and see if you get massive hs's.