My old military pal, an armorer, sent me two cans of this stuff. I first used it in my .44 Special. The action is remarkably smoother. Tried on a frozen bolt....worked faster and better than anything I've ever used. It ain't cheap. http://www.strike-hold.com/
After using Gibbs Brand I won't waste my time or money with anything else. You can check it out at Roadsters.com. Dave Mann the owner of the site is a member here and you can order it through his site. Frank
I use a mix of ATF and acetone, works better than any store bought mixture I've tried and is cheap, just watch out for the fumes.
If a military armorer is using the stuff on the job you can be ***ured it won't cause damage to any weapon parts. .
GM Rust Penetrant and Inhibitor part#88862627, sneek a can home from work and use on my projects. Works wonders.