I watched a video from winning in the wind . In it he said one of the chemicals in Free all was a solvent for nitrocellulose so it would work on powder fouling. I was wondering if smokeless powders are different enough chemically that different powder solvents would work better with different powders based on the chemicals in them. As an example, would freeall would work well on carbon from varget while not the carbon residue from H4350?
Burn carbon is burnt carbon, regardless of which powder it originated from. The primary difference between powders might be in the trace minerals (non-combustible) left in the carbon fouling. The important thing to consider here is the difference between a "solvent" and a "chemical reactant". Regardless of what some may claim, there is no solvent known to man that will actually
dissolve hard carbon deposits. At least not one that you'd ever put down a barrel. I'm talking about the burnt-in residue that looks like black volcanic glass. This would be analogous to finding a solvent that would dissolve graphite. Although graphite can certainly be broken down chemically, there is nothing readily available to dissolve it that we would ever actually put down a rifle bore. The same is true with carbon fouling. The only way to truly
dissolve such deposits is by initiating further breakdown via a chemical reaction; i.e. the use of a strongly oxidizing acid such as nitric acid.
No one in their right mind is going to do that to a barrel, so we are left with a couple alternatives. The first is mechanical action, such as the use of a bronze brush or abrasive cleaners. The second is the use of something that helps to "suspend" the carbon residue so that it can be carried out of the bore, again, primarily by physical means. There is a big difference between a suspension and a solution. It is likely that the use of penetrating oils such as Kroil or Free All is beneficial because we are not actually
dissolving the carbon deposits, but rather are lifting them up off the bore surface mechanically and removing them as re-suspended particles. Clearly, the penetrating oils seem to have a beneficial effect, likely both in terms of getting underneath the hard carbon so it can be physically removed from the bore surface by mechanical action more easily, and in keeping the carbon residue suspended once it has been lifted from the bore surface.
I have found Kroil helps in removing the black volcanic glass in the throat, but it really requires several days treatment; i.e. multiple wet patches/soaking a few hours/bronze brush treatment, repeated several times over the course of two or three days to really get most of it out. Having also used an abrasive cleaner (KG2) in the past for the same purpose, I'm not at all sure the Kroil treatment is any easier. Due to the comments in this thread, I have been meaning for some time to obtain some of the Free All and give it a whirl, but I never seemed to get around to it. I finally bought some a couple days ago and will give it a try.