If your scope has MOA adjustments, roughly 1 mil equals 3.5 MOA.
The specific dimensions of the scope and how you mount it to the base effect the zero when the adjustment is bottomed out. The larger the scope tube, the higher the center of the scope is above the bore. The further to the rear the scope is placed on the tapered rail, and the higher the center of the scope is relative to the center of the bore.
Thus, if you point of impact is too high when the rear scope ring is mounted furthest to the rear of the rail, move it a notch forward and with no other adjustment the point of impact has dropped. I found that to have a 100 yard zero, I had to move my scope ahead by 2 notches on the rail, but from that point I could use all of the elevation adjustment in the scope. A scope with a 1" tube will print lower than a scope with a 34 mm tube.