I suppose I could tell you a little bit about tumble lube pistol bullets, as I invented the concept, and the general lube groove profile as sold by Lee.
Superb accuracy can be had with tumble lubed bullets if the mould drops the right size bullets, a good tumble lube is applied, etc. and bullet production speed is wonderful. However I dropped it because it is suited only to light to moderate loads in most guns, and because sizing is mandatory to get top accuracy from several guns with one bullet, and perhaps worst of all, if the mould provides proper tolerances, and happens to be held open at all during the cast, the resultant bullets will hang up when chambered. If bullets with the same problem were to be sized, one would never know, either from the target or with shooting problems. A final problem is the loaded ammo is messy, and sticky gumbo messy with the Lee liquid alox. I personally can't stand the smell of it or put up with the tackiness on my fingers and everything the ammo touches
The reason velocity is so limited is because with fine lube grooves, too much lead is in contact with the barrel, not enough bearing surface floating in lube. If bullets with standard lube grooves are tumble lubed velocity is normally even more limited because the large grooves provide no hydraulic lube pressure, and if the bullets collapse at all due to chamber pressure, bullets go out of balance, which further hurts accuracy.
If you have bullets which chamber freely when not sized the best tumble lube you can put on is any one of the LBT bullet lubes, with commercial being the least tacky. - Simply warm the bullets, one layer deep in an aluminum cake pan, in a kitchen oven, to about 200 def F. Touch the stick of lube on the bullets or pan bottom so enough melts off so that when the bullets are agitated they are all uniformly wet ted with lube. Use no more than required to make the bullets look damp. When they cool, load and shoot. You'll be able to get a couple hundred FPS more velocity with this lube than with liquid alox, or any other tumble lube I know of. I got up to 1200 fps in cool weather. 800 to 1000 in hot weather up to 120 deg F. (
