Read the above comments with the understanding that accuracy is a relitive thing, and, maximum velocities are very limited, compared to LBT lubricant.
To get best results with any lubricant, the grooves must be full so hydrolic pressure is put on the lube as the bullets size down in the bore, and as obturation pressure is applied. With only a skin of lube, in that portion of the bullet which obturates, or upsets due to pressure, the bullet will close up till the lube is under pressure, but in closing up, deformation will unbalance the bullet and more bearing surface will be created. Un lubed bearing surface is the cause of early leading, when trying to work up maximum velocity.
For the record. I developed the fine grooved tumble lube process, had a mold cut for it, and developed a dry to the touch lube. It worked very well for light pistol target loads, and stood up to 1200 fps without leading. I wrote an artical about it in the Cast Bullet Association newsletter stating that I would be producing molds for it soon, and Lee promptly "inovated" it, before I could even get started. After more extensive use, I discarded the concept, because it is only good for unsized bullets, but sizing and a precise fit to the cylinder throats, (with throats/bullet slightly larger than groove, are mandatory for optimum revolver accuracy.
When I started LBT it was to provide better products and than any other manufacture, and the most scientific information available about cast bullets. I stick with that concept, and rather than change would prefer to simply close the doors.