And another thing about using oils like WD-40- the contents that are in a spray can are under pressure which means they're going to have a certain amount of moisture. Just another reason not to be spraying it on a gun. You won't have that problem with gun oil that is in a plastic bottle.
I really don't think there's any "moisture" (water) in WD-40. It is a water displacing product. If it had water in it, it could not displace water. Water would bond and mix with it.
This is an excerpt from a description of one of the ingredients in WD-40, Nonane. "Another alkane. One reason these molecules are so handy here: Their hydrogen atoms don't hold a charge, so they can't connect to the hydrogen or oxygen in water, which makes alkanes water-repellent. WD-40, after all, stands for "water displacement, 40th attempt."
Maybe I don't understand what you meant by "moisture". I have always thought moisture to be another way of referring to water.
