This is how I PC my bullets, the way you choose to coat yours or the process you use may vary from mine. As long as you get the results you like that is all that matters.
Convection toaster oven for curing your bullets.
I prefer the convection oven because it heats more evenly. You can pick one up at a resale store on the cheap or just buy a new one for around $30 to $40 depending on what you like. [b]ONLY[/b] use the oven for curing powder coated bullets or heat treating bullets from that point on [b]NEVER[/b] use it to cook food in afterwards. If the oven is not digital and controlled by an internal PID get yourself an oven baking thermometer (WallyWorld for $7) to set your temperature dial as close as possible, most toaster ovens don't heat to what the dial indicates. Set your oven to keep a constant temperature at 400 degrees, if the temp runs +/- 25 degrees it wants hurt anything you just don't want it to get to hot or too cool.
Plastic container for tumbling bullets in.
You will need a one or more #5 plastic containers and lids depending on if you want to do more than one color, screw on types are the best but snap on lid types like I use work fine to. I use these two types of #5 container I recycle from home along with multi color plastic pony beads I get at WallyWorld for $1.50 per pack, they are large enough that they want get stuck in my big 45 ACP HP's. The combination has worked well for me to generate lots of static electricity to attract the powder to the bullets, and it acts like a buffer between the bullets as well. One thing of note is that [b]LOW HUMIDITY[/b] is your friend as it will make generating static electricity easier, I like it to be 40% or lower. At times, I've had to coat in the house and take them out to my reloading shed to cure if the humidity is really high in my shop.
#5 container from local restaurants.
Great Value Yogurt container.
In the small container I place enough beads to fill the bottom about 1" deep, in the larger container I add enough to fill it between 1" an 2" but no more than that. I add about 1 TSP of powder to the container with the beads and shake it up for about 30 sec. notice how it already starts to stick to the beads and sides of the container. I always start out with 1 TSP if you need to add more powder to get the desired coat only add another 1/2 TSP to the mix as too much powders will clump on the bullets and you will have to tap it off before placing them on the baking tray. It's easy to add a little more powder to get a fine coating than having too much to start with.
Next I add the bullets. Make sure they are clean of any dirt, oil or lube or any contaminates that might be on your hands as the powder will not stick. I like to wash mine in 100% Acetone if they get handles much an wear nitrile groves when handling bullets I plan on coating. I generally add around 50 to 75 bullets to the container depending on caliber and weight close the lid and shake in all directions for around 30 seconds to a minute. I used black air soft BB's that I had with the clear powder coat, and they work great with clear, not so much with some other colors I've used but the pony beads will work with all colors. Another plus is that the pony beads are large enough that they want get stuck in the cavities of hollow point bullets like the air soft BB's will.
After about 30 seconds to a minute of shaking I tap the lid to knock any powder off the inside and look at my bullets to see how they are coated. If they pass my inspection they should look like this or the ones in the white clear coat above.
Next I take my baking sheet and line it with a piece of Reynolds Non-Stick aluminum foil, non-stick side up, there are cheaper brands of that type foil but I think the Reynolds works best and I get around 7 to 10 uses out of a sheet before I toss it, other like silicone baking mats but powder residue tends to build up over time on those, so I just use the foil, parchment paper for baking is also an option, I use it as well and it's totally no stick.
I take a pair of long tweezers and place all my bullets base first onto the foil or parchment paper, it takes some time to do it this way but I can easily have the next tray of bullets ready to cure by the time the first batch is finished curing. Many just dump the bullets into a screened tray, shake off the excess powder and dump them on the foil and bake, but I like the results I get standing them up individually and the powder flow and migrates evenly with no lumps or flat spots. For tall bullets that tend to topple over when moving work close to your oven and move slowly, nice flat bases are also help keep them stable while moving and is a plus when applying gas check either before or after powder coating.
Next I pop them in a 400 degree preheated oven and watch for the powder to gloss over or flow out as Eastwood calls it and then bake for 20 min. then I size and gas check as needed. Recently I started applying gas check to some bullets before powder coating as the powder will stick to the checks as well and makes it easier if getting the checks to fit onto some coated bullets gets frustrating.
Powders I like to use.
Smokes Super Durable Clear or Carolina or Signal Blue and Translucent Copper are all excellent powders to coat with. Smoke will sell you a pound of powder divided into 3 1/3rd lb. bags of his colors if you like for the same cost as 1 lb. of any color, but these are the colors I like and that have worked for me the best with no fuss.
A few notes on cast bullet air cooled or quenched from the mold and how the curing process will anneal the cast lead bullets using an alloy that responds to water quenching or heat treating. Your results may vary depending on the original alloy used and the as cast BHN and at the time the bullets BHN is tested.
1. If you air cool your bullets when cast then PC them and allow them to air cool again the second time there is no change in the as cast BHN of the bullet.
2. If you air cool your bullets when cast then PC them and quench them right out of the toaster oven they will gain a hardness of about 75% over the as cast BHN.
3. If you quench your bullets out of the mold to begin with then PC them and allow them to air cool they will soften around 50% from the original first quenching BHN.
4. If you quench your bullets out of the mold to begin with then PC them and quench them right out of the toaster oven a second time you only loose around 15% hardness from the first quenching.
Does Cast Bullet Hardness change after Powder Coating your results may vary.