WD-40 did well in this corrosion test: http://www.thegunzone.com/rust.html
However, they have some other comments about it:
However, they have some other comments about it:
Despite its good results, I would not use WD-40 for firearms unless I had little other choice. The "WD" stands for "water displacing," and WD-40 does that task well. That means it is good for hosing down and flushing out that duck gun that fell overboard, at least until you can get it home for a proper cleaning. However, WD-40 tends to gum and turn into a varnish with time. So WD-40 may be fine for an external wipe down, but it is potentially devastating to moving parts that require lubrication. In my experience, WD-40 has little, if any, lubricating properties, and is best left for its designed tasks.