A gun that is wiped down with a oily cloth is fine. If your gun is loaded I would't have more oil in it, or on it, than a light wiping. You can always give it another wipe anytime you want.

If you've oiled it so much that oil will collect in recesses by gravity feed, or is observable in fine drips down the inside of the barrel, or the firing pin hole clearly is saturated --- then that it too much for a loaded gun in my opinion and for that matter a bit overboard for an empty gun as well. Once the movable parts of an auto-loader or pump action are clean and dry a light wiping is more than sufficient for storage, unless you live in a very corrosive environment. Remember, you can always give them another wiping periodically.