WD40 is NOT a lubricant. Its a water displacerOil base products like wd40 etc will break down rubber that's why silicone is used on o rings. I have used Napier as its stated use is pellet lube although i have no idea what its made from.
WD40 is a penetrating oil, light weight lubricant, etc. that also displaces water. If one were to look it was actually developed as a lubricant to be used in orbiting vehicles and machines for the space program.WD40 is NOT a lubricant. Its a water displacer