Oil has three functions: lubrication (friction reduction), corrosion reduction, and wear reduction. At the same time we want to minimize fouling buildup and maximize reliability. Not all of these goals are complementary. For me the goal of reliability in a carry gun trumps all the others. Whatever you decide to use, test your system! I have found that a very thin layer of some lubes can attract fouling.
"I have one simple request... and that is to have sharks with fricking laser beams attached to their heads!"--Dr. Evil