I have seen many threads where an owner put a gun in one or another type of case, left it there for a while, and was surprised to find rust.
Shotgun, rifle, pistol, revolver. The worst were stored in cases that had foam inside, but anything that prevents airflow works to encourage rust.
I have seen those gray cloth chemically-treated rifle storage sleeves that claim to prevent rust. I also see some yellow poly sleeve/bags that claim the same. I have not tried either one, but if I used one, I would not trust it enough to leave it for several years without a glance.
This test shows the relative corrosion prevention of a number of products.
Rem-Oil ends up in the middle...not terrible, but far from the best.
Eezox ended up the best, and it is what I have been using since I saw this test...and another that had similar results.
Good luck, and let us know what works (or doesn't).