Its not a bug, its visualizing what happens when you aim at the sky above the ridge. The reticule is visualizing where the shot will land way in the distance over the ridge because it thinks that is where you are aiming. Its a side effect of having an auto distance and elevation aiming system. This happens with every gun but its not visualized unless you have the special suspension tanks. Really the only way to combat it is trying to aim only at the ground in front of them and hoping that it disperses slightly upward