here is what I do not understand

[Joe Gussenhoven]

First group looks normal. Correct wind deflection for a right hand twist barrel and no wind flags.

Lower target same thing except the four vertically strung shots.

The targets indicate a good consistent load. So, if the four high shots are the last shots in that ten shot string, I would guess that you are reacting to the recoil and pushing forward against the butt. If shooting off cross sticks, will force the muzzle up. Of course it could be something else. I have a .38 Badger barrel that did that. The bore had no taper. I lapped a taper into it and shrunk the groups in half.
Have you tried a dry last patch?

Joe.