Calculating bullet trajectories has become a simple task with computer programs doing all the mathematics. A simple but adequate (and free) program for ballistic calculations is PCB, writen by Odd Håvard Skevik. On the basis of a few input paremeters, a trajectory can be calculated. For instance:

As such, this is of little relevance for an ISSF sport shooter. After all, the target is always positioned at the same distance, and the trajectory of the bullet between the rifle and the target is not too informative.

More interesting is the possibility to investigate the effects of certain variations on the point of impat on the target. For instance:

- In what direction and how far does the point of impact move when the rifle is canted (still maintaining the target and the sights perfectly alligned, as illustrated below)
- Does the use of riser blocks affect this point of impact displacement for a given cant error?

PCB offers the possibility to calculate these effects. In a
series of *articles*,
some results of calculations and experimental validations are
presented.