I have to differ with the post of Mr. Hansam
WD-40 is not a solvent. The name itself WD stands for water displacement and in the inventors chain of events he achieved his goal on the 40th try, hence the name.
It primary purpose is to displace water and prevent corrosion. Although it,s composition is proprietary,and we don't know its composition, it does serve as a light lubricant, very similar to 3 in 1 oil
I believe there is enough lube remaining for an auto loading pistol action. I clean my auto loaders with WD-40, let dry and then use a teflon dri-lube spray on the action. On the outside I use birchwood casey Barricade products which also is a rust preventative.
If you have time to do it twice, then you have time to do it once right and put your name on it