BTW, my rule, which has been working for many years, is to give every metal surface in/on the gun at least a film of lube/preservative. For the barrel/chamber, which I usually clean using the CLP of choice at that time, the last thing I do is to run a brush through it with a patch on the brush with the CLP on it. This leaves just a film of lube. Its for this reason that I never have problems with extraction. On an AK, the 'film' treatment naturally includes the gas piston, gas block and piston tube. 'Every metal surface' means just that. I never get rust and the gun is always easy to clean after shooting. And if something were to happen after cleaning/lubing the gun so for some reason I didn't get back to it for an extended period, I know it would be okay.