At what diameter do your tumble lube bullets mike? I assume you're going with ALOX lube?
For tumble lube with Lee Liquid Alox, the preferred method is thus:
Tumble lube as cast. No sizing. Pour a 1/4 measuring cup of LLA diluted 1/2 with Mineral Spirits* into a .50 caliber ammo can. Close can and slowly rotate can end over end for about 3-5 minutes. Slowly. Rough tumbling damages bases. Not good. Open can and spread bullets out on cheap dollar store cookie sheets covered with wax paper. Allow to air dry overnight. Load as is.
Here is how we do it:
We put roughly 1,000 .38 Special Wadcutters (The Hensley & Gibbs #50 Bevel Base) into a .50 can. Pour the LLA over the bullets. Close can. Slowly tumble end over end. Open, pour onto wax paper, dry overnight. Load the next day with a target load of bullseye. Little to no crimp. Accuracy with a Colt Target .38 is <1.5" at 15 yards, all day, every day.
*C.E. Harris (or Ed Harris as he is known today) is an advocate of diluting the Lee Liquid Alox as it comes from the bottle. He cuts it at least 50% with mineral spirits to further dilute the mixture. Once you have coated your first batch in the .50 caliber ammo can, for further batches you can reduce the LLA amount poured into the can by roughly 50% (I use a common plastic coffee scoop as my measuring device). So, one coffee scoop of LLA diluted 50% poured over 1,000 H&G #50 wadcutters is sufficient lube for target loads.
We shoot as cast, unsized. My Ruger School gun shoots this load with WW .38 Brass all day and makes beautiful cloverleafs as long as I do my part.
If you're going to cast your own wadcutters, semi-wadcutters, or other styles, for lubing with LLA, you need to cast uniformly frosted bullets. The frosting, when examined under sufficent magnification (100x to 500x) will reveal micro pitting in the lead surface that allows the LLA to cling to the projectile surface.
Uniformly shiny lead bullets, while pretty, will not hold the LLA nearly as well as uniformly frosted bullets.
If you like pretty bullets, then you want to go the sizer/lube route. Try a Star Sizer (the best), Lyman, LEE, or SAECO. With a soft lube, and a sizer die of the appropriate size, you can attain as good results with considerably more labor.
Casting your own is a very enjoyable activity that is rewarding and economical. I've grown so addicted to casting that I own bullet moulds for calibers I don't even own guns in. I made my own casting pot after years of frustration with commercial pots. I've been known to haunt the off ramps near the interstate on weekends walking the curves with a 5 gallon bucket picking up wheel weights.
Yeah, I am hooked.
:-D