Advice Needed - Front Sight Adjustment

[Surpmil]

You could scribe a discreet mark on one or both sides of the blade where it abuts the base, then loosen the locking screw, or not, depending on your tastes, and tap the blade in the opposite direction to which you want your group to move. If you loosen the screw you may not need to tap the blade at all: you can move it with your fingers. It goes without saying that you should only tap it near the bottom, not on the actual blade. The scribed line(s) will enable you to see how much you have moved the blade from your starting point.