Ive had this problem a lot of places actually, but an example can be found at:
Example is X: 3540.65 Y:4928.86 Z:204.61 GRID: 035049 The imidiate rocks to your SE.. Prefrably spawn as autorifle with tracers.. Step about 10 meters back and you'll notice the bullets hit\bounce ab out 30cm above the actual rock..
(remember to take into account your sights is mounted above your barrel ;))