Sarg

I had a mate who I bought a 65 Carcano for - at his request LOL.

Let's say the bore was far from perfect, like yours full of crap, rust etc.

Anyway, the next time I saw it, the bore was nice and shiny
and I found out that he shoots FMJ's through bad bores to clean them up (after using Wipe Out to get most of the crud out).

FYI, Wipe out Foam bore cleaner cleans rust off really well
including really caked on rust. I found this out after using it on a "tin can" that had spent 6 months in the great Sand Pit where out Military forces are. Worst case of cleaning I've ever come across and it stripped it back down to the base metal inside.

Anyway, good luck with your project.