There is a reason why am thinking about this. I just had a gun bore scoped, and it had small pits in it. It only has 700 rounds thru it. I may be my well used dewey rod. But I used wipeout for two years on this gun. And always cleaned it until there was only faint blue with sweets. Hopeing there wasn't a reaction between the sweets and wipeout. I always put 4 patches thrubefore changing cleaners. Sometimes used brake cleaner between solvents. I have dozens of guns, and never had this problem particularly.

There was a period where I didn't clean so aggresively. I would use shooters choice only, and left most of the copper in it. Would only spend 15 min on the barrel max. I then decided to decopper and thats where I had to go to the real heavy duty JB's. And as everyone knows JBs leaves that thick black residue and can be hard to remove all the way. I know with medocre cleaning you can end up with layer of hardened carbon and copper. And the carbon has by products that can pit.

Just trying to figure out the mystery so it doesn't happen again. Still shoots ok. Just fouls more.