Old 454 Let's see if we can help you get some better results with you powder coating. I did some NOE 124 gr. TC bullets yesterday in purple an clear coat as well as some Lee 185 gr. RN in Signal Blue.
First off I do my coating usually outside in my building but sometimes I have to do it in the house if the humidity is too high an bake on the back porch, I like it to be around 40% or lower as it helps create static when the air is dry.
I start off with a container like this one as I've found it works the best for me. They are just recycled #5 plastic containers and lids that we get takeout in from the Chinese restaurant or you can just pick some up at the restaurant for about a quarter each.
I fill the container about 1" deep with these plastic beads you can get at any Walmart or craft store cheap. You can wash them off and reuse again an again if you want to switch colors.
I put about a 1/2 tsp of powder in with the beads and shake it up for about 30 seconds to get everything mixed well, you may need to add more powder but I only add about half as much 1/4 tsp as too much can make the powder clump on the bullets, you just want a fine coat. As you can see the powder is already clinging to the plastic bowl.
I hold the container like this in my hand an swirl everything around for about a minute sometimes less or if your lazy and need to do something else you can set it in your tumbler for a couple minutes.
I place all my bullets on nonstick aluminum foil base first an bake at 400 degrees for 20 minutes.