Has anyone tried or been using this stuff? I have for awhile now and although it states that it won’t cause rust I have a factory savage that says otherwise. I use this on this savage because it has a rough bore and collects a lot of copper. But this last time I noticed some rust in the action area because of the foam coming out of the bore as it expands and sits in just before chamber area. Also I took it out of the fibreglass stock to find more rust around action area probably because foam expanded into action area. I lost confidence in this stuff although I don’t have to slave away putting patches down the barrel.