I finally picked up a Hawkeye borescope and all I can say is wow I should have got one a long time ago. I just scoped one of my 22-250's and after cleaning it using my normal routine (wipeout or Butches with a nickle plated jag ) I cleaned it untill there was no blue on the patches and was very surprised at how much copper was still in the bore, this was a factory barrel but the most accurate one I own.
I was also surprised at how little fire cracking was in the throat/bore of my 20br after almost 500 rounds compared to a 22-250 at 500 rounds the 20br had only a very small amount around the throat and the 22-250 was about 6 to 8" of the barrel ahead of the chamber and I was pushing both of them pretty hard.
I think this is a great tool well worth the money compared to what some people have tied up in firearms
I was also surprised at how little fire cracking was in the throat/bore of my 20br after almost 500 rounds compared to a 22-250 at 500 rounds the 20br had only a very small amount around the throat and the 22-250 was about 6 to 8" of the barrel ahead of the chamber and I was pushing both of them pretty hard.
I think this is a great tool well worth the money compared to what some people have tied up in firearms