Rust on my rifle

[Squirrel8811]

So I open my gunbag at SoGo last weekend and this is what I find.  I keep it in my office in the bag and sogo is the only place i play so the only source I can think of is sweat.  Any idea of, first how to get it off without damaging anything, and second prevent it in the future.

[wanna b bada$$]

Steel wool is what i would use. To stop it from happining agian hit it with some hair spray every once in a wile. It keeps my welding bend tests from rusting in the bottem of my tool box.