The way firearms are best stored these days is how the military do it...VPCI bags.
These special "hard" plastic bags won't pass moisture like ordinary plastics will and they have a material that generates a vapor that drives out moisture and oxygen.
This vapor surrounds the metal and totally prevents rust for 10 years or more.
These are sold under names like Z-Corr and others.
You can buy them on eBay and Amazon.
https://www.amazon.com/s?k=gun+stora..._ts-doa-p_9_11
A major advantage other then totally preventing corrosion, is that you can take the gun out of the bag, wipe the bore out and go shooting without any messy grease removal.
This is why the military now store weapons in these bags.