Back to storage protection requirements being related to weather conditions, ie: humidity where you are storing your guns.
Here in BC, spraying with WD 40 after cleaning and drying, is all that is needed - for at least up to 20 years storage - stored muzzle down for the ML's and butt down for the modern stuff.
Thus, if the Ml's or other guns are stored in a climate controlled safe, about any sort of oil after cleaning will work. If they are stored where there is gross temperature fluctuations or high humidity, you need a more aggressive rust preventer than WD40 or Hoppe's #9(not plus), Outers solvent or whatever.