Goodbye bullet lube, goodbye leading

[Yondering]

Thought I'd share my recent experience here with coating my cast bullets to eliminate bore fouling. This is by no means my own idea; guys in Australia and parts of Europe have been able to buy commercially coated cast bullets for a while now. Here in the US though, it's just now catching on, with a lot of experimenting how to do it best.

I'm dry tumbling my cast bullets in ordinary powder coating powder, and baking them, to get a reasonably even powder coat over the whole bullet. This means no exposed lead, no lead/bore contact, and no leading (or any other metal bore fouling, just powder).

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 powder I'm using is TGIC Polyester from Powder Buy The Pound. I ordered a bright green, and a iridescent green.


I use a plastic yogurt container to tumble the bullets. With dry tumbling, you can't really get too much, the excess powder just stays in the bottom. I shake the container by hand 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.


After baking for 15 minutes (the directions say 10 minutes, but my garage is cold and the toaster oven is small)


Sized and ready to load


More bullets.
- The .30 cal rifle bullets are working fine at 2000 fps in my 300 Blackout; trying them in my 308 next. The one at the back right was recovered from a subsonic load; it penetrated about 18" of alder log, and only shed a little of the coating on the nose.
- The expanded bullet in front is from the loaded rounds in the center - 9mm 125gr Mihec mold, with modified shallow hollow point pins, 6.0gr WSF for ~1220 fps. This load needed aluminum gas checks to prevent leading with traditional bullet lube, but now the coating is completely intact around the base and bore contact surfaces with no bore fouling at all.
-The 200gr 10mm Mihec bullets on the left show how the hollow points get nicely coated too.

[The_Shadow]

Thanks Yondering, there is a guy down here (Bayou Bullets) in the area that is selling his bullets with the coatings on them already.
He also sells the product to do them yourself as well.

If I recall, they are adding a acetone solvent making the powder into a slurry that adheres to the bullets, as the solvent evaporates it leaves the bullets evenly coated.  Then they bake them and size to finish.  I posted a link once to the video a guy made using the product.

[Caneman]

Great info Yonder!!! i gotta give this a try   

edit:  found some fairly priced TGIC Powder on evilbay

edit to the edit:  apprently the boys on castboolits found powder coat epoxy at Harbor Freight for $6 per lb.

[Yondering]

Thanks Yondering, there is a guy down here (Bayou Bullets) in the area that is selling his bullets with the coatings on them already.
He also sells the product to do them yourself as well.

If I recall, they are adding a acetone solvent making the powder into a slurry that adheres to the bullets, as the solvent evaporates it leaves the bullets evenly coated.  Then they bake them and size to finish.  I posted a link once to the video a guy made using the product.

Yep, Bayou I think is the first commercial loader to sell these. That's the easy button if you don't cast your own.

I tried the acetone method, and didn't find any advantages over tumbling them dry. Coverage is about the same, and you have to wait for the solvent to dry before baking them, which takes longer than you'd think. That's what guys on the castboolits forum are doing though. Dry tumbling works the same, just skip the acetone and dry time, it's not needed.

I'm tumbling and baking ~ 100 bullets at a time in my little toaster oven, and found that once I get going, I can load the first 100 bullets while the next 100 is baking. I'm able to convert lead ingots into a couple hundred rounds of loaded ammo in one evening with this method.

For pretty bullets, the best method is still the normal powder coat gun of course, but that's a lot more equipment and setup time.

[The_Shadow]

Are you doing the powder shortly after casting?  By that I mean you are not preparing the bullets by any wash process, because they come straight from the molding process.  Yes one person was using the spray on powder coating method with a  slight charge to attract the powder.

These poly coating are tougher and much better lube properties and sealing than the spray paint I messed around with for the Zombie looking bullets!

I'll have to get some and try an play with this someday! 

[Yondering]

Correct, straight from casting to tumbling. As long as your hands are clean, you can handle the bullets before tumbling, and don't need to wash them in solvent. I've handled most of mine before tumbling, picking out the rejects and scraping off the flash from one of my rifle molds; the powder coating still sticks fine.

[wifecallsmegrumpy]

 

Nice work Yondo.  I have been using these for years and had great accuracy and very little leading. They are not perfect and I still get some leading, particularly in the compenstated guns.
I'd imagine as the process becomes accepted amongst your current bullet manufacturers they will become the norm.

How about some accuracy testing ?

[Caneman]

Yonder, have you tested out the .308 rifle bullets yet?  I just bought a 7mm-08 and would like to shoot some cast where i did not have to worry about leading issues... are you still using a gas check? I was thinking of loading it down to about 2100 fps and this would just be for practice rounds only.

[sqlbullet]

What is the baking temp, and can you quench them from the oven to get some hardness in antimony alloys?

[sqlbullet]

Just ordered a lb.

[cwlongshot]

Pretty neat!!!

CW

[Ramjet]

I have done the coating from Bayou bullets the key is to have the temp of the bullets at the 375 for at least 4 minutes I have a cheap small convection oven but need to upgrade to a bigger better one. But in my Henry (should say my sons via confiscation) Henry 45 Longcolt  running coated bullets over 1600 FPS no leading.

[Yondering]

Nice work Yondo.  I have been using these for years and had great accuracy and very little leading. They are not perfect and I still get some leading, particularly in the compenstated guns.
I'd imagine as the process becomes accepted amongst your current bullet manufacturers they will become the norm.

How about some accuracy testing ?

Yeah, it's weird how the US is so far behind you guys in this.

My coating may be a bit thicker than what you guys buy commercially, I'm not sure. I'm getting zero leading in my pistols, but I don't own any ported barrels anymore. I don't think a brake would do anything to these bullets, but a ported barrel is still likely to cause gas cutting through the coating.

I didn't take pictures, but did some accuracy testing the other day with these coated bullets in my 9mm - I couldn't quite tell if the accuracy was better than the same bullet with bullet lube, but it was at least as good. Definitely positive results so far.

[Yondering]

Yonder, have you tested out the .308 rifle bullets yet?  I just bought a 7mm-08 and would like to shoot some cast where i did not have to worry about leading issues... are you still using a gas check? I was thinking of loading it down to about 2100 fps and this would just be for practice rounds only.

Haven't had a chance to run them through my 308 yet. I have been shooting them in my 300 Blackout though, using the Lee 155gr 7.62x39 bullet. I saw some slight leading from these at 1800 fps without a gas check, but with a check (applied after coating) they are shooting like jacketed bullets, but without the copper fouling.

I think you'd do fine at 2100 fps, but I'm hoping to push them a lot faster than that.

[Yondering]

What is the baking temp, and can you quench them from the oven to get some hardness in antimony alloys?

Baking temp depends on the coating you order. I'm using a TGIC Polyester that says to bake at 400* F for 10 minutes. I'm doing 425 for 15 minutes, just to make sure the bullets heat evenly all the way through (I want them softer).

I think you can water quench them if you want, although I haven't tried. I don't think these coated bullets need to be as hard to resist gas cutting and give good accuracy, so I'm using straight wheelweight alloy and letting them air cool. (see the expanded bullet in my pic above, I can't do that with an uncoated bullet unless I use a gas check)