[R. Scott]

I never had a problem using WD 40. Spray it down and wipe it off. With automatics, I would use a light coating of lithium grease on the slide and rail.

[ExSoldier]

I never had a problem using WD 40.

What is the worst sound in the world? Hearing a click when you expected a BANG!

Just because it's never happened to you, doesn't mean it's not a common occurence. It does happen all the time. Speaking as an NRA Instructor, I strongly advise against it. There are PLENTY of products designed for this specific use: I use Rust Prevent but there are tons more.

[RadioAstronomer]

never had a problem using WD 40. Spray it down and wipe it off. With automatics, I would use a light coating of lithium grease on the slide and rail.

I like trifon (triflo) better. Not sure you can get it anymore.