I've tried just about everything, and I've found it best to just stay on top of things. I clean my rifle after every range session. I don't care if I fire ten rounds, or one hundred. I clean my rifle as soon as I get back home. Having said that, keep in mind I don't detail clean the rifle every time. Most of the time, I simply clean the bore and chamber. Then I wipe down the bolt assembly, charging handle, and the inside of the upper receiver. I then re-lube and put back together. No scrubbing or scraping. Every third range session, or after alot of shooting, I detail strip, scrub, scrape, and break out the q-tips and pipe cleaners. I use PB Blaster penetrating oil to clean, and I re-lube with a good heavy gun oil. I avoid cheap russian ammo, because it's too filthy. I try to shoot good quality ammo. You would be surprised how much cleaner the rifle stays when shooting good ammo, versus the russian stuff.