Angle Compensating Rnge finders
Angle Compensating Range finders work out to a point, however they are merely utilizing the "Rifleman" method of determining the "Base" of the triangle. When utilizing an angle compensating range finder, there can be as much as an eight MOA error when shooting at longer distances and while holding on steeper angles.
The Rifleman method is the Least accurate of the three methods used.
The most accurate method for determining your hold on target is to utilize Ballistic targeting Software such as the one that Night Force sells. This is because the software takes into account the BC of the bullet, the bullet's weight, the bullets unique velocity, your zero distance, along with current temperature, barometric station pressure and humidity. With this data, the software will calculate the bullets unique deceleration curve, which you can then take a step further and validate the bullets trajectory. This may sound like a lot of stuff... However it is really very simple and will deliver a very accurate hold.