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.

hate the stuff for most uses [it has some]

I use it on my guns after a day in the rain

Local "experts" that I know say to steer clear of it, too much kerosene in it.

Yes WD-40 is great for guns!

Others are full of it when they say it’s worse than water, they don't have a clue what they’re talking about!

WD-40 stands for

Water Displacement and it’s the 40th Formula!

It’s fantastic for putting a light corrosion preventative coat on metal and a light coat in the bore. Using it as anticorrosion for the bore doesn’t affect the accuracy on the first shot as oils like Break-Free®. However after stripping the bore of a copper, Break-Free® is my #1 choice to reimpregnate the metal to greatly reduce copper fouling. Just remember to shoot 3 rounds before shooting for accuracy and use WD-40 to clean the bore after the 3 shots.

I've used it for over 20 years on guns. Any lube will 'gum-up' a receiver if you use too much and don't clean it enough. I usually use WD as an 'outer coat' on my guns, and a squirt of Rem-oil in the actions. This is all done after a thorough cleaning w/ Butch's Bore-Shine, Hoppe's #9, and Bore Scrubber

"WD" stands for Water Displacement. It is primarily used to temporarily displace water for troubleshooting of electrical problems. Then it evaporates and it's gone. No residual lubrication. No rust-proofing. I used to know someone who raced a highly-modified Triumph on the motorcycle short track, and he showed me what it was for. On a very humid night, he hosed his ignition system with it and sprayed his points while it was running. It cleaned them and it never missed a beat and he won.

When you shoot the 3 rounds before shooting for accuracy and use WD-40 to clean the bore after the 3 shots, you can store your rifle for the season and when season is over, strip the bore again and use Break-Free® to recoat the bore.

Beekeeper, even if you used the best gun oil it will eventually breakdown into like Cosmoline. The bottom line is how efficiently you clean it and don’t blame WD40 or anything else for someones lack of cleaning! I remember I had to use automatic transmission fluid on my rifles to function properly!!

I use carburetor cleaner first to strip all the oils, carbon and other unwants off the firearm. Then a give it a bath with Coleman Kerosene to remove any leftover chemicals and anything else. It also prepares the metal by stripping all the left over carburetor fluid and deeply impregnating the metal with a superlight coat of oil residue so oil can penetrate and bond like a cast-iron frying pan. Then a light coat of WD40 or gun oil depending on the elements the firearm will be exposed to.