Buck

Looking at yur target, I gather you are aiming for the middle of the circle ? It just looks like R3 AND L3 had a different sight picture when you fired.

Might I suggest putting a 1" white sticker (round)
on the black part at 6 o'clock and aiming for that ?

The 1" white circle is easily covered by the front bead
and the Big black circle will nestle into the V of the
sights, thereby making sure you have exactly the same sight picture each time.