Can anyone provide a picture of what a “carbon ring build up” in the camber or rifling looks like? I hear a lot about it but wondering what it looks like with a bore scope and also wondering the easiest way to remove it, is?

Easiest way I've found is CLR

https://www.24hourcampfire.com/ubbthreads/ubbthreads.php/topics/18021811/hard-powder-carbon-removal