The knock on the egg crate foam is that it is supose to hold or retain moisture. I live in Colorado were humidity isn't a big concern plus I rub my pistols down with a good protective oil. I had a S&W 586 stored in a pistol case like that for nearly 15 years pretty much untouched and there was only on little speck of rust that I found. Your mileage may very but if the shotgun is in constant use and care I see no problem. Spray the foam lightly with silicone spray will also help.