I would try some carburetor cleaner if its that tough of stain to get out. carburetor cleaner will take out stains in a bore that regular gun cleaners wont sometimes.

I had something similar in my bore after firing and I used a wire bore brush with some solvent on it. A couple of strokes and it was gone.

What do these "spots" look like? I had a triumph barrel Crack on the inside and buldge on the outside after only 40-50 shots. Be careful about sending your barrel bac to t/c, get ahold of them BEFORE you send them your stuff, they have had my barrel since the week between xmas and new years and I have not heard a thing from them! I have left several messages and sent several emails and have not heard ANYTHING!

I have had a ton of people tell me "T/C is the best, T/C has always taken care of me," Well I'm hear to tell you T/C SUCKS ! bring your gun to a local gun smith and get the service you deserve friend.

"Spots" in the bore? Guess I'd have to see them myself before I could give any advice. Were they there when you cleaned the bore prior to initial firing? Have you cleaned the gun after each use?

Do they seem to cause any problems with loading, like do they cause the bullet/sabot to hang up? Do they feel like a rough spot? As others have said, solvents will remove anything on the surface of the metal. Not sure they'll help with anything in the metal.

If they are just a cosmetic issue I would not worry about them. If they do seem to be something that grab the sabot or bullet, or perhaps even something in the steel that should not be there, I would send it back. I would also talk to T/C before sending.

BUT, don't be shocked if it takes a few weeks to get a new barrel for freeif you should send the barrel back during the holidays when a company is running skeleton shifts due to vacations. Boy wouldn't that just suck something awful!?!

hard to believe they dont help you.

T/C has always been good to me on my lifetime hawkins flintlock.