I fully know that this is in contention but being old gives me some license to say what I think.
With one caveat, WD-40 should never come closer to a gun than vermouth comes to gin.
If one wishes to free up a rusted part, it has some place but far below BreakFree.
If allowed to remain in moving parts until dried, it will cause more problems than is solves.
I sincerely advise it not be used on guns and other fine working mechanisms. It is NOT a lubricant and has no lasting quality other than becoming a hard coating that gums up the works.
All one needs is an oil and then clean with an oil remover.

Best,
John


Humble member of the League of Extraodinary Gentlemen (LEG). Joined 14 March, 2006. Member #1.