Gun socks can trap moisture and make it worse..../ just depends on the environment more than anything ( humidity / how warm it is / how cold it gets at nite ).....
Its the simple things....like putting a gun safe on an external wall of your home - where the wall gets colder than an internal wall...can make a really big difference.
Its kind of like - where will mold grow.../ air circulation ...all that stuff matters. It isn't inherent that plastic cases are bad ...with or without a sock may not matter ...may make it worse ...may make it better....just depends....
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