He used a traditional Ideal (Lyman) 158 gr mold that had the single groove for the lube. You didn't say if you used a LEE mold, but they do sell TL (tumble lube) molds that leave a number of smaller grooves on cast bullets, instead of one large one like the Ideal. If you are casting with a TL mold, they recommend using them "as cast," and not sized. Have you tried that? If so, how did it work compared to the sized ones?
SmittyJon (Chris Mitchell)