I agree with the above accessement of the right target. Unfortunantly, that isn't confirmed by the left target! Including your first targets, I see no indication of any "sweet spot" or node in your tests thus far.
Perhaps your limited range of charges isn't wide enough to find a node. Or, just as likely, that powder and bullet combo simply isn't working in your rifle.
I doubt that load increments of .1 gr. will help until you get a better grasp on what works.