Thanks for the suggestions. I may try soaking the barrel and then cleaning it again. I really think it is just carbon, but I could be wrong. Again, the photograph greatly exaggerates the density of the rough spots in the barrel. The light source is at the end of the barrel, so some of what we see in the photo is shadow. Plus, with the photo stacking technique needed to get everything in focus over the length of the barrel, there is some chance for overlap, resulting in further exaggeration. I took this photo several times before I got the lint from the cleaning patches out. The tiny threads were tack sharp, however, and very distracting.
This is the barrel that was in the gun when I made all the 100-200 yard P-09 videos shown in my YouTube channel JoeMustang99. I haven't shot it much since getting the 97B"E" and the P-10 pistols. The P-10F barrel is just as good at the range, and looks to be manufactured using exactly the same techniques. I sure hope so. The P-10S 3.5" barrel is the one I should be studying, however. The P-10S has taken over 1st place in my favorites list after getting the results I got at 200 yards. Unbelievable. Modern manufacturing techniques are phenomenal.
I also have a regular Lyman borescope that I can use to get a right angle view, greatly magnified. Last time I checked the bore, that stuff looked like carbon, not surface damage. But I'll look again. If I can get a good shot of the P-10S barrel for comparison, I'll do that, too. It has maybe 2k rounds through it.
Joe