Thread: dirty barrel.

hey guys ive got a question, and would love to know your thoughts and would really appreciate some advice.
i have a mosin nagant i clean it with sweets 7.62 solvent and the riffling comes out very shiney but the lands in between the rifling stay really dirty like a residue or something. that runs the full lenght of the barrel.. i use a 303cal brush to scrub it.
ive tried carbon cutter but that did not do anything. its got me so stumped.
the bore is in choice condish. cheers fellaz