WD-40 is a poor lubricant and a lousy gun cleaning solvent. (“WD,” incidentally, means “water displacing.”) While it may have some utility in removing moisture, that’s about where it’s value ends. Aside from being a poor lubricant, it also tends to oxidize and gum in short order, making it a poor choice.
Anyone interested in bore solvents should consider making a gallon of “Ed’s Red.” (C.E. “Ed” Harris was a chemist and technical editor for the NRA’s American Rifleman magazine. He devised a modern equivalent to the old Frankfort Arsenal Nitro-solvent Gun Cleaner No. 18. as detailed on page 352 in Hatcher’s Notebook.) It works exceedingly well for modern, corrosive and black powder cleaning. To wit:
Combine 1 quart of deodorized kerosene, 1 quart Dextron automatic transmission fluid, 1 quart mineral spirits and 1 quart acetone into a suitable container. (A metal can works best. If you choose to use a 1 gallon fuel can, replace the neoprene gasket with one made from cardboard gasket material, purchased at your local auto parts store. Acetone will cause the neoprene gasket to soften and swell.)
That’s it! If you choose to go the extra mile you can add 1 pound of anhydrous lanolin (available by special order at some pharmacies) to the mix and stir well. Ed’s Red is an outstanding cleaning agent, combining polar and nonpolar solvents (mineral spirits, kerosene and acetone) with a lubricant with exceptional stability and antioxidant properties (Dextron ATF) and a polar “grease” (lanolin) for long-term protection. Best of all, it’s cheap and easy to make.
A fine resource on “homebrew” firearms cleaning can be found here.
For those without the patience to wait for their order of lanolin to arrive, an even simpler and highly effective solvent can be found here. Regards, – Moriarty
JWR Replies: Thanks for your comments. I must add one other warning about the solvent WD-40. It is notorious for deadening primers in ammunition. Keep stored ammunition in sealed cans, separate from solvents and paint cans.