Picked up 2 Mosins 91/30s a few weeks ago. Both are Tulas 1934 hex receivers and my first mil surplus rifles. The bores on these rifles just keep pouring out gunk. My procedure is to wet patch, sit 20/30min, brush and the dry patch. I've been doing this a few times a night for 3 weeks now. Tried a number of different products: Hoppes 9, Birchwood Bore Scrubber, Shooters Choice, Break Free, WD-40, PB Blast, and good ole hot soap and water. Will these bores every come completely clean or is it enough already?