Glocks are set up to shoot at point of aim; front sight covering what you want to shoot. OVER the bullseye, not under it at the 6 o'clock position.
Edit: 6'clock refers to directly under the bullseye; so 3 o'clock position would be at a 90 angle from the 6 o'clock position. 12 o'clock would be directly opposite the 6 o'clock position.