I'll give it a try tomorrow or the next day. Got some new walnut shell and Turtle Wax rubbing compound, and have a blade running in that right now. I had started with Cabela's red-treated walnut shell, but I think that was jeweler's rouge and it did nothing to the steel blades.

I did speed up loading the rubbing compound by cutting it into the shells as the tumbler ran. Think adding cold butter to sugar, or lard to flour. Same action. Ask a baker if this makes no sense to you.

My Naniwa 12k should arrive today, so I'll have that much more lapping grit to add to the corncob. I'll have nothing to compare to, since this is my first go-round with the tumbler. I know that early in this thread people did very nicely controlled comparisons. Unfortunately, I can't quantify my grit size or amount, only whether grit-loaded paper towels will give up the grit to the media.

I could sacrifice 1/8" of a coticule, add x teaspoons of lapping dust to x cups of corn cob, but then someone would want to know whether it was better or worse than if I'd used LPB or La Veinette. Not going near that can of worms, not me!