The one time I had a severe bedding issue. The shots would walk from center bellseye to two o'clock. Each shot rising higher to the right as the barrel heated up.
My stock was warped, and pressing on the barrel in one direction. Some careful inspection should reveal such a flaw without too much trouble. I'm not a gunsmith, and was trouble shooting without much knowledge or any experience when I figured out the problem.
The other culprit could be scope or sight related. Five inches is a lot for the same ammo.
