PART ONE When I bought my rifle a few days ago it was absolutely flawless. The inside of the barrel was really shiny and the piston had no discoloration at all. Everything was spotless. The guy I bought it from said he'd put 300-500 rounds through it before it became a safe queen for a few years then was sold to me. I shot it yesterday (100 rounds of Wolf FMJ) then took it home and cleaned the crap out of it. No matter how I scrubbed it (or with what), the piston would not get clean. When I got it, it looked like this: Now it looks like this: What gives? PART TWO How should one clean an AK to perfection? Any links or tips would be appreciated.