Home Forums Reloading Bullet Casting Dry tumble powder coating

Right about a year ago I tried powdercoating my cast bullets by tumbling in the dried powder, and have been using that method since then. (Other people were tumbling in powder/solvent mixtures, which gets messy and time consuming.) I thought I'd share my process and experiences here, after mentioning it in a couple other threads.

The whole process is pretty easy, about the same effort as tumble lubing, but without the wait time for it to dry. My process, from melting pot to loaded ammo, is as follows:
- cast bullets
- dry tumble in powder
- bake 15 min
- cool 5 min
- repeat tumble & bake
- push-through sizer
- load ammo

The best powder I've found is a "grass green" TGIC Polyester from Powder Buy The Pound. I've used a bunch of other powders as well, and each one acts differently. Some form a very tough coating, but the bullets stick together too much, while others don't stick to the bullet when dry tumbling. Don't waste you time with the Harbor Freight powders.
My favorite powder:


I use a plastic yogurt container to "tumble" the bullets, but any recyclable plastic food container should work. I use a few teaspoons of powder for 50-75 bullets. Shake the container by hand (shake hard!) about 20-30 seconds, until the bullets are evenly coated. This is the second coat on these bullets:


Then dump them out in a tray. A bit of metal screen on the bottom keeps the bullets from getting a flat spot in the coating where they touch the tray. Don't touch them, the powder comes right off at this point. If there's excess powder in the tub, carefully pour the bullets out without dumping out the powder too.


Bake for 15 minutes @ 400* (the directions say 10 minutes, but my garage is cold and the toaster oven is small)


I typically apply two coats of powder (2 cycles of tumble/bake) for most bullets, although some claim good results with one coat.

Then size as necessary. I use Lee push through sizers, they size more concentrically than the Lyman style, and are faster. If using gas checks, apply the checks first, do not size before putting the checks on.


more coming...