User blog comment:Gershtoot/Blops PC Patch released with interesting sniper tweak/@comment-122.106.217.64-20110424055400/@comment-216.137.201.81-20110424065529

It's the fact that the auto-aim makes sure that it hits, and since most of them are a kill to the chest or above, it is indeed OP. You aren't using the gun correctly. It would be like finding an exploit where shotguns had infinite range and were still lethal.