-- Last Updated: May-09-12 10:41 PM EST --
I have not recommended cleaning the gun with WD-40; just as a wipe on the surface. I might add that WD-40 has been successfully used to maintain M16 combat rifles. ANY oil that gets on a primer or into a cartridge case may cause a malfunction so it doesn't matter if it's WD-40 or something else. There should be no "loose lubricant" in a rifle barrel or action. Sealing the cartridge as I've described eliminates problems. When I was on the U.S. Army National Match Rifle team in the 1960's, we lubricated our match rifles with motor oil. Really, motor oil. About then, a synthetic oil called "Anderol" was developed and some of us switched to that. The .45 pistol shooters literally squirted it onto the slide so that it dripped off. The procedure kept those tight slides cycling. The type of lubricant simply isn't problematic. Having an over-lubricated gun,is. I've had less than a dozen missfires in nearly half a million rounds fired in small and big bore competition and my rifles were lubricated with everything from 3 in 1 oil to motor oil to now, the newest synthetics. The missfires I've had were never due to lubricants; they were the result of light primer strikes/bad firing springs or badly loaded ammo. It's not a big deal, really--that is, if you use some sense.