Sorry, my friend...been on a hunting trip for last 10 days and may have missed it....difference between what and what?
Remaining carbon does act as a lubricant. The problem is consistency. I measured uncleaned brass using residual carbon as lube and the seating forces were not as consistent as using a lube. Here are plots from my AMP Press dry graphite vs raw, lightly brushed necks - both done same day, same batch of brass:
I tried two methods. In my opinion, the immersion method gives a more uniform and consistent layer. But it requires removing the residue from OD of the neck( an extra step in the process )
I hate dry tumbling that has all that dust and aftermath as well. That why I really like tumbling with rice. Haver you tried dry tumbling with rice (that is, medium grain rice)? If not, give it a try. You may be surprised???
It dries completely after half an hour, leaving a thin layer of graphite on the surface, which allows the mandrel to pass through the neck much easier than without. I use it mainly to improve the sizing process, although I also noticed an improvement in SD .
Yeah, I too get just a few cases with grains of rice in the LRP pockets. I find they're easily removed with a small screwdriver.
And with wet tumbling, there's the hassle for drying out the brass.
I've not ever use walnut or corn cob having often read about the issue concerning dust. Since I didn't wand to deal with the dust issue, I was wet tumbling without SS media until I heard about dry tumbling with rice and it's lack of dust. I was skeptical, as I often am about things I hear, but will try things anyway to see what I get for myself. The rice was surprising good at cleaned my brass well enough for me (you see my picture above) and I've stuck with it for years.
