The muzzle velocity of the load being used and the ballistic coefficient of the bullet were determined beforehand from manufacturers data, chronographing the loads, and actual trajectory data measured when loads are fired at several distances to validate the results.

To achieve accurate trajectory predictions it is also necessary to know the actual barometric conditions at the range. Here the shooter is using a device that measures temperature, pressure, and wind velocity.

Exbal is a powerful tool at the range. The actual barometric and wind conditions are entered to refine the trajectory calculations.

Notice the right handed shooter with the left bolt. This allows him to reload without losing his "cheek and palm weld" on the stock. This has big advantages in timed events.

The rifle is sighted in at exactly 100 yds.   The shooter then adjusts the windage and elevation on the scope by  the number of "clicks" indicated by Exbal.  The result is a perfect shot at 600 yards. The group fired in this session was 2 inches in diameter at 600 yards, 3 o’clock in the 10 ring.

This technique is easily extended to make a perfect shot at any target distance by using a laser range finder, mil-dots, or other range finding technique to know how far the target is away.