My basement, where my guns are stored, is very dry in winter and during non-heating season I run a dehumidifier, not for the guns, it’s just so the basement doesn’t get musty. I have often, for months at a time kept airguns in the typical egg carton foam cases with zero rust. Unpainted bare metal does not rust in my basement. Lucky I guess.
My cases only go to the range and back or hunting and back. And they are never exposed to rain. If for some reason it’s rainy I will leave case open in basement to drop the possible humidity it absorbed.
The big plus on airguns is the majority of components are anodized aluminum and plastic, maybe some brass and stainless steel too. Typically the barrel straw is steel and that of course is the main worry.
I remember when pretty much all AR-15’s came with the now “coveted” white straw that was maybe treated with something to prevent bore rusting. An AR from back in that era is worth even more money if you still have the stupid straw. Collectors, God luv em.
I recently bought two Flambeau cases just for my Evol and Paradigm. They came with some dividers that are treated with something to prevent rust. I put them in even though my basement is dry. They create two rectangular areas for small odds and ends so they don’t end up hitting rifle, and would be a perfect place for some of those slica gel moisture absorbing bags.
Flambeau does caution in their instructions though that the egg carton foam could leave marks (shadows) on the blueing and recommends putting rifle in the plastic bag the rifle came in. To me an enclosed bag, and any moisture, is a recipe for disaster. My Flambeau’s don’t leave any marks but any exposed parts on my Evol and Paradigm are anodized or hard coat anodized, not blued steel. In my opinion, blued steel is much much more prone to rusting than any typical PCP. And that’s where springers come in, they are typically blued steel. I keep those in my gun safe. I can never hold on to anything so I try to keep them as factory perfect as possible because I never know when it will go up for sale.
There used to be a product called VBI, Vapor Barrier Inhibitor, which was intended for gun case, machinist tool boxes, etc. Not sure if they still exist. They were small foam blocks treated with something to eat moisture or exude some magic film.
