Using gun oil to remove the preservative ...is less than satisfactory in my view..../ and WD-40 used to work way better than it does now ( because the propellant in WD-40 up until about 15 yrs ago was "propane" ...up until the late 1990's ...) and now its just C02 ...but it still works ok..../ and better than oil ... ( but some of us old cheap guys / still have a can of the "good ole stuff" with propane in it, laying around...)....
From WD-40's website ....
" .... I've heard that people use WD-40 as a cleaner/remover. What can it be used on?
WD-40 removes sap, tar, adhesives, labels and tape from surfaces without damaging existing paint. It's an effective cleaner for tools, equipment, and vehicles. Use it to remove splattered bugs from the front of cars. WD-40 will even help remove gum from carpet. Just spray, wait, and wipe with a clean cloth........
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When I was a kid....and it still had Propane in it ....we used it as a "starter fluid" into the carburetors on old trucks in the winter time..." ...but we were young and stupid ..../ when it had Propane in it, as a propellant, there were people that got hurt spraying it into live elec switches like on home clothes dryers, etc...cans exploding, etc..../ but with CO2 that is no longer an issue...
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and WD-40 claims ...."
While the ingredients in WD-40 are secret, we can tell you what WD-40 does NOT contain. WD-40 does not contain silicone, kerosene, water, wax, graphite, chlorofluorocarbons (CFCs), or any known cancer-causing agents.
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so I use a lot of it ...on the outside of my guns..../ shotguns and handguns...and then wipe them down...
At Costco recently - I even picked up a 12pak of WD-40 in small 4oz cannisters ...easy to throw in a gun bag / gun box..../ and a little can in the car / and one in the shop,,,,,