I don't see any "abuse", the crown looks good for a well used rifle. I would give it a thorough cleaning that starts with Remington 40-X bore cleaner(Walmart has it cheap) and a tight patch on a brass jag. Follow up with Hoppes to remove all traces of the 40-X, then a light coat of oil. I bet those "chips" you're worried about will disappear when you're done.
http://www.remington.com/products/ac...e-cleaner.aspx