See John, that's part of the challenge.

I can and do shoot well with irons, three hundred yards isn't very easy, but I know I can do it with express sights.

What I want though is to have targets that make sight regulation as easy and repeatable as can be.
The target shown above is close to 'really good'
The horizontal lines at nine and three o'clock and the vertical line at twelve work very well to refrence the bead.
I think that using a black background with a white 'dot' big enough to show juuuust a ring of white around the front sight (which is black with a red fiber optic rod) to repeatably show where the front sight's sitting on target might be my next step in getting closer to an ideal target.

I do like a challenge.
Practice at 300yd with irons is a bit of a challenge.
With practice shooting game with an accurate rifle at 300yd over irons is practical.

--Tinker