There is a product available that works great with cast bullets that I have been using for the past 12-15 years called " ROOSTER JACKET " BULLET FILM LUBE.
http://www.roosterlabs.com/products.html . Using H&G 9 cavity molds or greater 380 through 44 , star luber /sizer dies and equipment. When casting I usually cast around 5000 projectiles at a time. To use this liquid product, let your projectiles cool enough to set then immerse them into the rooster lube ( I use an old 50 cal ammo can with a wire strainer - - like a french-fry basket) keep immersed for a few minutes then drain excess back into your bucket and spread the projectiles over a wire mesh to dry for several hours. You can then size them through your sizer without the mess of stick lube and heaters. The lube will penetrate the pores of the lead. My customers have never complaned of leading problems or bore fouling. The lube may be cut with distilled water if the lube is too thick for your preference, I usually cut it approx. 50%