I use to think I was pretty darn good at cleaning and keeping all my firearms clean and protected. Last night I purchased Barnes CR-10 ammonia based cleaner from Bass Pro Shop and started cleaning according to the directions. If what I was seeing on the patches (blue) color then there is at least some residual copper fouling in most of my rifles. I have used most all the standard products that we have over the years but now I wonder if what I'm seeing is something I've overlooked or didn't know about until now. Looking for thoughts on ammonia based bore cleaners. I did follow directions and cleaned up with Rem oil to stop any ammonia barrel corosion (spell).