I've shot a fair amount of my Grandfathers lead-cast reloads. I'm not entirely sure of his casting processes, lead mixtures, and such but I always found his lead reloads to be smelly/smoky/dirty. The plastic ammo boxes are permiated with the ammo stank, and I can always tell what brass had lead in it because it seems waxy almost.

 

I have some of his bullets (which I haven't attempted to load), and some lube sticks. The cardboard with the sticks says it is a 50% mix of Alox 2138F and 50% pure yellow beeswax manufactured by Javelina. Is this an overly "clean" or "dirty" lube? I would be interested in casting if I could find something that shot clean. The bullets he cast are sticky to touch. There was no excessive leading, so it did do a good job shooting. 

 

Oddly enough, I shot some cheapo Magtech 38 LRN this week and it was impressively clean.

You're on the right track in that it's not so much the composition of the lead bullet that is creating the smoke and undesirable characteristics above but it depends more heavily on the lube used on the bullets.  I have no other insight for you than this though.

I should add that the cast and lubed bullets are sticky. Thanks for the insight

There are different lube mixes for different applications. I have some red lube that is very sticky and some blue that is not. Allox and bee's wax is very common. Hot weather, cold weather, rifle, pistol, etc. I cast 30 cal. for milsurps and some 38 wadcutters. There is a wealth of expert advise over at Castboolits. Hope this helps.