I havent posted here in a long time! The G3 series of rifles are dirty pigs. That being said, it doesn't seem to effect function. I have run these things where they are filthy, greasy, full of carbon. The G3 just doesn't stop in my opinion. So if you clean it religiously, great. If you don't, it will still run like a raped ape regardless. It has a bit more recoil than most 7.62 guns, but it works and requires very little service or attention. As said above, it is almost impossible for you to pound enough rounds where you need to worry about rollers etc. If you do, you are an unemployed millionaire to be able to afford the ammunition and time to make that rifle fail.