Just got hold of the game and trying vanilla. Does anyone know how the sight works? I understand the principle. If an enemy is filling a small triange he's at 1000 meters. Let's say he is just 300 meters away. I then tap alt +/- to adjust the sight so it's above the enemy and then depress the gun so that the sight (top of big triangle) lines up .

But what about the alt + and alt - adjustment, how does each increment relate to the range?