The sensitivity and FOV changes depending on certain actions and where you are (indoor etc). The calculations are for the view when you move around outdoor.
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Update: After lurking various topics and whatnot I found a config that feels nice for insurgency sandstorm, which I had trouble making it "feel" right
For long range scopes (x3, x4, x6, x7) I set MDH to 100% and 50% for mid range scoeps (x2, x2.5)