Another example of home grown ingenuity, applying an industrial process created for a different purpose, yet ingeniously applied to the world of firearms.
The italicized words below are that of the author, enjoy!
A couple points first:
- This process works best with larger batches of bullets, at least a few hundred at a time. If you're trying to coat only 50-100 bullets at a time, don't expect very good coverage.
- Powder choice matters a lot. Skip the Hobo Freight powders, they really don't work as well.
- Container choice matters too. The white plastic yogurt or sour cream tubs always work well for me; don't substitute other container types. I suspect these containers build up static to aid in coating.
- Finally, I don't make any money off of powder coating or posting this, I'm just sharing to help out fellow casters. If you prefer a different method, that's fine with me. My method is optimized for fast, easy, and efficient coating, not for aesthetics.
These are 9mm 105gr hollow point bullets from a Lee mold I modified. I shoot them at 1450 fps from my Glocks, so the coating has to be pretty tough. That doesn't mean it has to take a long time to apply though. The pics below illustrate less than 1 minute of effort on my part (other than taking the pics) for coating, and another 8-10 minutes for separating and sizing about 200 to 250 bullets.
A quick note about powder BTW - not all powders are equal, in fact, none of them are equal, in my experience. Each one behaves slightly differently, even just different colors of the same brand/lineup. The powder below is RAL 6018 Yellow Green from Powder Buy The Pound
About this much powder for one coat; this is roughly 200-250 bullets. Use a plastic recyclable yogurt or sour cream tub.
About what it should look like dumped on the bullets. If you get the quantity right, the bullets will be coated like below, with little or no extra powder left in the tub
5-20 seconds of shaking by hand, hard. I do mean shake it hard; build up some static in there by swirling the bullets around, and get that powder floating around in the air. If you're holding the tub in one hand, you aren't shaking hard enough. You should feel like you got a little exercise from shaking the container of bullets.
Dump them out on a tray, doesn't matter if they touch each other. I use a metal screen in the tray to avoid flat spots. Note - the amount of bullets shown here is kind of a minimum for good results; I'll normally coat 3-4x more at once, they'll be piled several layers deep on the pan. Do not touch them with your fingers!
The Toaster Oven is nothing special, just the old one from the kitchen that I salvaged when the wife wanted a new one. I keep it in the garage next to the welder. Yes, it's ugly, I use it for all sorts of nasty work-shop stuff, it's OK to laugh.
One very important detail - use an oven thermometer to figure out baking temp, do not trust the dial on your toaster oven. I've shown my thermometer in the oven in these pics, but now that I have the correct setting figured out, I don't normally put it in there. Notice my dial is up past 500F, but the actual temp is right about 400F. Some ovens may go the other way. You can bake the powder coating for a long time without hurting it at the prescribed temp, but if your oven gets too hot, you can burn the coating or even melt your bullets into a puddle. If it's too cold, your coating won't fully cure and will not be strong.
A guy could also control one of these toaster ovens with a casting pot PID and thermocouple, but I've found mine is pretty consistent even with large batches of bullets and when the garage is really cold in winter.
Dry coated bullets placed in the oven, note the dry/dusty looking powder on them:
My oven usually gets up to temp in ~6-8 minutes, and the powder coating melts over the bullets as you see here. Appearance of the bullets won't change for the remainder of the time in the oven, as long as it doesn't get too hot.
20 minutes bake time in the toaster oven at 400* F (temp varies for different powders). You MUST use a thermometer to verify oven temp. Do this in the garage, not the kitchen, unless you're planning to get divorced soon.
Separated, ready to size (use a push-through Lee sizer die). Notice the thin or bare spots, and marks from the screen and touching other bullets - those don't matter. These bullets pictured are every bit as accurate as any jacketed bullet in my Glocks, and will chew out the X ring at 10 yards. These have only one powder coat and are adequate for most pistol loads; you can do a second coat before sizing if you want better coverage. I don't recommend more than 2 coats.
More points to add: As you may have noticed - no need for lube grooves with powder coating. I ream or bore them out of a lot of my molds; they cast easier and grip the bore better. That Lee bullet still has the lube grooves, I just haven't got around to boring it out the rest of the way.
There is a surprising variation in different powder coatings, in coverage, slickness, and toughness. My best results are all with TGIC Polyester coatings from "Powder Buy The Pound" (spelled buy, not by) in the RAL colors. I'm using a Bottle Green now that also works great.
Breaking apart the cake of baked/coated bullets can be tedious. I get most of it broken apart by dropping the tray repeatedly on my concrete shop floor. Bullets do go everywhere, but it saves breaking apart by hand. There are always some clumps that still have to be broken apart though. When I find a couple bullets glued base to base, I just throw them back in the casting pot, it's not worth trying to separate them.
Powder coated bullets should be sized after coating, not before. (There is no reason to size both before and after.) Variations in coating thickness and the occasional sharp edge where bullets stuck together needs to be sized down. I prefer my bullets to cast a little over final diameter, then combined with the coating I'm sizing down at least a couple thousandths.
The fastest sizing method for coated bullets is the Lee push through dies. They work really well, with one caveat - every last one of them needs to be polished inside; Lee makes them look good on the outside but leaves the tapered portion inside pretty rough. I polish with emery cloth on a split steel 1/4" dowel chucked in a cordless drill. Generally I buy the sizing die a thousandths or two smaller than my desired final diameter, so it'll end up at the right size after polishing. For 9mm for example, I use a .356" die polished out to .3575".
With these dies, I typically can size ~250 bullets in 10 minutes. I do this while waiting for the next batch of bullets in the oven. If I coat in 500 bullet batches, I can coat and size 1,000 bullets in about 1 hour.
A possible improvement on the sizing process could be to use a powered bullet feeder mounted on the press. I haven't done this though.
Bullets from some of my molds accept gas checks after coating without issues. Others won't without shaving coating and/or lead, no good.
My solution is to flare out the gas checks a little. I made some tapered punches to fit the gas check sizes I use; I made some punches to fit a lubersizer but the hand punches are a lot easier. Sometimes I'll use a little mallet but really hand pressure is enough to flare the checks. Then they fit onto coated bullets easily. It takes a little more time to do this but is still faster than a lubersizer, and I don't do rifle bullets in as much volume anyway.
I would like to see copper gas checks available that are a little looser fit for coated bullets; they don't need to be so tight before sizing, and it wouldn't affect use on non-coated bullets at all.
Here are some more examples of my coated bullets:
If you can recover any of your fired bullets, examine them! The condition of the bases and bearing surfaces can tell you a lot about how your coating is holding up.
A few handy pictures of some of mine, not all were successful:
One more thought, about personal health when doing this - powder coating, because it is such fine dust, is hazardous to your body and you don't want to inhale it.
When I first started powder coating, I just put powder in a yogurt tub and shook it, but I'd notice a bit of powder dust in the air afterwards. Now I've learned to put the container in a gallon ziploc bag and seal it up before shaking. You can see powder in the bags in the pic, that's what came out when shaking. I'm going to add this pic to the OP because I think it's important.
I still tend to get some on my hands, you may want to wear surgical gloves; personally I just wash my hands after and avoid touching my face. Just exercise some caution, whatever you choose to do
