What is the worlds best sniper rifle?

The sniper with the most confirmed kills is Mikhail Surkov,a Soviet sniper who fought in ww2 credited with 702 kills

There is also a sniper during the finish winter war who was credited with 505 Russian kills( without a scope on his Finnish Mosin-Nagant rifle), he is ALSO credited with over 200 enemy kills using his submachinegun, bringing his total confirmed kills to a minimum of 705

http://en.wikipedia.org/wiki/Simo_H%C3%A4yh%C3%A4