I completely agree with Jim's assessment of WD-40. I have used the stuff by the gallons over the years for two specific things. Help loosening rusted fasteners on farm equipment, and moisture displacement in the barrels of muzzleloaders immediately after cleaning the bores. I have since dispensed with the use of it on rusty fasteners as I have found something much better called ZepPreserve. But it is still as good as anything out there for moisture displacement.
When cleaning m/l barrels water or some form of water "agent" is almost always used. After graduating from the old hot water method I tried many concoctions, all of which worked pretty well. I have for the last ten years or so used a mixture of alcohol, Murphy's Oil Soap and hydrogen peroxide, in equal parts. It must be kept in an opaque container such as the peroxide bottle, but is super. After drying patches WD-40 is used to remove any trace of moisture. Then it is removed with dry patches and RIG is applied to the bore for rust preventative. Never have had any rust to appear after this treatment, even when the gun sat for years.
As Jim tried to explain, WD-40's bad rep has come because of it's misuse. It certainly has gummed up the insides of many an auto, but unnecessarily.
