Make sure bullets are CLEAN. Swirl, swirl, swirl, swirl, shake hard, shake hard. Use good powder. Preferably from Smoke on Castboolits.com. He also has a list and pics of which powders work best. Has to be a "shiny" or metallic powder. Matte or flat colors you're pretty much wasting your time. Some say the humidity needs to be pretty low. Go over to castboolits.com and read, read, read.