The Ballistic Coefficient (BC) is used to do external ballistic analysis. The most common use is to input the BC into a ballistic computer program along with other data about the shooting conditions (muzzle velocity, zero range, atmospheric conditions, etc) in order to calculate a trajectory for the bullet. The trajectory information is used to make sight corrections for drop and wind deflection.
BC’s of various bullets are often compared when selecting a bullet for a particular application where external ballistic performance is important. One example is long range target shooting where the shooter wants a high BC in order to minimize wind deflection. A high BC does not indicate a more accurate bullet. However, a high BC does minimize the effects of many shooting variables like uncertainties in range and wind conditions. Through minimizing the effects of the uncertainties, the higher BC can reduce the net miss distance compared to a bullet with a lower BC.