It's not really that hard Luke. There are basically 2 subtension units in that reticle--1 mil, and 1/2 mil. 1 mil=3.6 inch per hundred yards [IPHY] or 3.44 minute of angle [MOA]. That optic also has a turret that adjusts in .1 mil clicks. This is really nice since it's very easy to click from one line to the next. In other words when you run a ballistics program for your load, and fine tune it, then if a 575 yd. shot calls for 4.7 mils. you simply go up 2-.1 mil clicks and aim at the 4.5 mil mark.
Or if it's quite windy and the dope calls for 3.5 mils elevation and 2 mils windage, then crank up the entire 3.5, and aim into the wind 2 mils from x-hair axis.
Very simple system really.
Rangefinding is also made easier since you don't have to guess [interpolate] the entire 3.6 IPHY opening. The .5 mil mark is there which makes breaking up the unit easier.
The formula is
tgt. size ["] x 27.8 / mil. reading = range [yds.]
A 1/2 mil unit can actually be used for rangefinding even more accurately but the math becomes a bit more complicated if anyone's interested i can detail it, but the above will certainly get you started.
