I have tested it and currently use it on my Kimber .45. I have tested it, but not yet made a decision reagrding its use on my Patriot Arms .308 or my Hammonds Custom .308.
On my .45 it works great. Good lubricity (is that even a word???) and retains its lubricating ability even after several hundred hardball rounds through the firearm in one day without cleaning. It also seems to make clean up easier. I used the lubricate and fire method of application. After the 3rd application and firing, it was noticably better lubricated and easier to cean. In fact some parts simply wipe down with a rag and they are completely free of carbon fouling.
Some have not had the same good results as me, but I believe it is worth a test (I mean they give free samples for testing so its not going to cost you anything!!!!)
For my .308s I'm just a bit more hesitant to do do a full blown hundred rounds dry test (but I do use it on the bolt and action). I'm currently using it in tandem with my Tetra Gun grease and there are no problems.