I am curious as to where the pictures were taken inside the barrel? On the one I have there is some erosion in the barrel at where the top of the powder charge would be at 40 grains of powder. Since I use 80 grains I am past that and found the original owner shot short range muzzle loading matches only out to 50 yards so that charge would work. I also found when I talked with him he was a smokeless long range shooter and cleaned this rifle like he did his 308s and 6mm guns which was not real good. He won all the matches he entered and got tired of the black powder shooting and moved to 3 gun competition for more of a challenge. Try shooting some patched round balls and check what the patches look like, if all torn then there is a problem otherwise it shouldn't matter.
John