Man have you ever Played Fallout 3 or New Vegas? can you make V.A.T.S, It's a targeting system that shows different body parts of the target and gives you percentage that you can shoot the target in different body parts, You can check Youtube For Videos if you don't have Fallout.
My PC Specs:
Intel(R) Core (TM) i5-2400 CPU @ 3.10GHz 3.40GHz
RAM: 8 GB
GFX: Nvidia GT 440
OS: Windows 7 32 bit