Does this help?
Mount the shotgun and obtain a good cheek weld on the butt stock. Look through the shallow channel machined in the top of the receiver and focus on the front sight bead. To obtain proper sight alignment, visually center the bead in the middle of the channel. You should see only the spherical bead. To engage a target, "put" the bead on the center of the target and press the trigger. The pellets will pattern on the target around your bead. If the pellets pattern high or low, you can either adjust your sight alignment (see more or less of the front sight bead - this may require slight adjustments to you cheeck weld) or adjust your sight picture (by adjusting your aim point in relation to the target).
The only way you'll know for sure is to get out there and test your patterns.
Cheers!