So many variables. Basically a gun will last a long time with almost no care. Its how some of us have managed to own fair size collections of guns in pristine condition. And back in the past they didn't have witches brews of wonder drugs like we do today.
Basically, for rust to form there must be bare metal, oxygen, and moisture. You can attack all 3 with only minor effort. Go buy some CLP Collectors (it kind of dries to a waxy substance). Clean your gun really well. Use powder solvent and generally make it white glove clean. Then if its a blue gun, slather a little more than usual of the CLP on the exposed surfaces. Keep a small camel hair brush around for fun. Its not made from camels, no camel jockeys, no terrorists. Is Squirrel. But its soft and you can use the brush to smear all the oil into a fairly level coating, and into all the cracks like the barrel frame seam, etc.
When you're happy with it, bag the thing. Go to your local supermarket and buy the thick, high quality bags like ZipLock brand (the idea is not to buy the economy bags that are so thin they come with holes.) Place the gun in the bag and kind of crush the bag to exhaust as much air as you can, as you close the seal. On nickel guns the same thing works, except you might be better off waxing it.
Now take the gun and just put the bag in a box. The original one works well because its sized right. Or one for a similar gun. Dant here on the forum usually sells dozens of them. The box prevents other guns from bashing together while still taking up little extra space.
Air and moisture can't get to the guns, and the boxes prevent abrasions. You've got life made.
Properly cleaned and lubed guns don't need a goldenrod if bagged. The air can't enter the bag and bring moisture along with it. Every so often you can reapply the oil if it makes you feel better. But its not necessary.