I just bought a Nylon 66, looks pretty good, when I disassembled it for cleaning I was shocked, this rifle has never been cleaned! The carbon buildup is incredible! Soaked in Kroil, nothing, soaked in Barnes solvent, still won't touch it. On the carbon I can easily get to I can scrape it out but, what can I use for a solvent in the nooks & crannies? Appreciate your input. Thanks. Roza745