Difficulty removing light rust?

[monotonous_iterancy]

I'm removing rust from some guns, and the strange thing, is that pitting rust is coming right out. Yet around some of those deeper patches is what appears to be a lighter surface rust, it almost looks like a stain on the bluing. It's especially visible under a bright light, like a flashlight.

It's not really coming off. I'm soaking these guns in Liquid Wrench, and using it as my suspension, yet these stains are still there, even though the pitting rust is easily removed.

Is what I'm seeing actually rust, or is it a discoloring of the bluing?

 

[rcmodel]

Bluing is rust.

You may or may not see a red color under or in it under certain lighting conditions.

Try 0000 Super-Fine steel wool & oil to remove all the rust that can be removed without harming the bluing that remains under the rust.

rc

 

[monotonous_iterancy]

I see. I'm thinking that it might be surface rust, but it doesn't come out so easily. I know that bluing is a form of rust, but these are splotches around pitting rust, which makes me think that it might be active rust. And if it is, shouldn't it come out easier than pitting rust?

 

[788Ham]

Get a "real copper" penny, using the edge only, put a little oil on the rust and scrape the rust gently, see if that helps.