Not familiar with the gun bag you're referring to. Idk. Stored on its side... Really doesn't matter, as long as the sights aren't knocked around. Scopes and sights will be off if they get knocked around. The line up is: Start with a clean and we'll oiled firearm. Coat all metal parts with axel grease, including the opening to the chamber and the end of the barrel. The most important part of the whole thing is water displacement. Old or new firearms, doesn't matter, if you're looking at long term storage, make sure water won't be an issue. If the metal has a coat of axel grease, water can't get to the metal. Whatever container you choose and where you store them: Water. Make sure water can't get into that container. If there's any signs of rust, make sure to eliminate with those first. Rust has a funny way of reproducing. If you're storing for years without looking at them, this is where you're starting point is. If you're looking at 6 months in a closet, just a wipe down every few months should be fine. (If there's rust, once a month, no rust, two months.) If you're buring them, it's all about coating with grease and picking a trusty container.