Powder coating lead bullets – dry tumble (DT) method
This is the method I now use to powder-coat (PC) pistol and rifle cast bullets. I use this method, because it worked so well from the very first try. It can also be called ASBBDT “Dry tumbling using the AirSoft BBs as a tumbling media”, because I use BBs too. I did think about getting a spray gun but after achieving good results with DT, I never looked back. Use of a spray gun is called ESPC method = Electrostatic powder coat (applied with a spray gun using a static charge). You can always buy an Electrostatic PC gun to get the smoothest finish, but it comes with more setup, more cleanup time and some powder will be lost. There are other methods in PC that I did not try (piglet method), different variations of DT (bake in a pile, drop into water). There is also Hi-Tek (powdered Hi-Tek + acetone). This post is about the simplest dry tumble method (DT) so let’s start.
You will need:
- Plastic container with nr#5
- Airsoft BB’ (optional)
- Blue Nitrile gloves
- Long needle nose pliers/tweezers
Powders: advice – start with already tested powders, which are proven to work with DT method. That way, you don’t need preheating, vibratory tumbler, washing them in acetone….just 60 seconds of shaking and swirling. No need for second coating either if you follow the instructions. I did and I had success from the first try.
I was watching my friend fiddling with the many local powders available to him (which he had to buy), spending so much time cleaning bullets and jars after his unsuccessful tests. I went for the easy way. I admit, I am sometimes lazy and I want good results fast, but I also read and I rather learn from other’s mistakes and from their tests.
I was also lurking at http://castboolits.gunloads.com for many weeks before deciding to step into powder coating. There are some forum members who were testing different methods of PC. Among them was a gentleman with nickname Smoke4320. He is now a vendor sponsor from USA who sells powder. He started to test different powders from big companies and he made a list of powders which worked with DT method. In spite of me being overseas in Europe (consider postage, customs…) I ordered his powders twice and never regretted that decision. After 3 years I still use powders from his first shipment. I would recommend anyone in the USA to start with his »DT tested« powders.
Call 704-624-4115 or email email@example.com to make an order. http://castboolits.gunloads.com/showthread.php?241259-Hi-quality-Powder-for-DT-or-Spraying-bullets
Plastic container with snap on lid, with triangle and #5 stamped on the bottom – very important to get necessary static (cool whip containers….) A round shape makes swirling easier.
Oven You need convection oven (air flow = heat distribution). A convection oven with a fan will distribute the heat evenly throughout the oven and will give you an almost sprayed slick look. Aim for 400F/200C. Bake for 20 minutes. If the oven is preheated to that temperature before putting bullets in, bake for 15 minutes.
You must be sure what temperature the oven is actually cooking at. If you can’t verify the temperature (I did, and it was off as expected) do a few small batches of 10 bullets till you find at what temperature YOUR oven gives a nice, even flow to the powder…too cool and you get clumps.. too hot and you melt lead.
Airsoft BB’ (optional) I wrote “optional” since Smoke’s powders work without them (dependent on the colour), but I almoast always use BBs, it just gives me the confidence that I am not going to damage my relatively soft lead bullets. The plastic BB’s lessen the impacts and somehow improve the static charge. They also remove excess powder from bullets which at the end gives a perfect coating. The black air soft work the best. BB’s are different plastics & weights. I have few colours; my black, yellow and orange work very well. But I once got white BB’s that were very smooth and they were useless.
Blue nitrile gloves Blue nitrile gloves can be used to pick up bullets. Other gloves have proven to not work, as they will remove powder everywhere the gloves touch.
Long needle nose pliers/tweezers Some use long handled medical forceps. I use modified tweezers, with bent tips. Dip the tips in powder and coat them a bit. It will then leave no marks on the bullets when transferring them to the tray.
Take plastic #5 container, add enough Air soft BB’s to cover bottom with 2 to 3 layers . (about 1/2″ deep)
Add between 30 to 100 bullets. (smaller ones like .223 would be 100, larger ones like 45 ACP 230’s might only be 30 at a time).
Add 1 teaspoon of powder for the first load if you have new BB’s and container. Remember that less powder is better as you can always add more.
1/2 teaspoon is more than enough for next batches.
Close the lid and swirl like crazy for 30 seconds, then shake fairly hard up and down for another 30 seconds. I swirl, shake, swirl, but I always end with shaking up and down. With some powders or with high humidity, you might have to shake up to 2 minutes.
Open the lid and check the coverage. If you see there is no powder left at the bottom, and the coverage is not good enough, add a bit more powder and repeat swirling and shaking.
Pick up bullets one at a time with tweezers or nitrile glove. Tap tweezers/pliers on container edge if necessary to shake off excess powder back into the container. You can also blow excess powder with breath.
I pick my rifle bullets with tweezers and sometimes pistol bullets with nitrile glove. I dip the tip of my tweezers into powder first. I dip the finger tips of my glove into powder too. It will not remove powder when picking coated bullets. You can use some kind of strainer too.
Put bullets on tray lined with non stick foil/parchment paper (will last many cycles). Some people successfully use silicone mats for baking.
Put in the oven for 20 minutes. (or 15 if preheated) Set to 400F/200C.
Take them out of the oven and allow them to cool. (you can quench them in water too if you want). There is actually a method where you bake bullets in a pile and then, after baking, drop them immediately in water to prevent the bullets sticking to each other. It is faster, but appearance is not so perfect.
If you water quench your bullets straight from the mould, before coating, the PC curing process will negate the first water quenching so you will need to re quench them after removing them from the oven.
- Replaces lubricants / less mess
- Not sticky (clean seating dies)
- Sometimes faster then alox/lubrisizer (depends on your method)
- Cheaper – use of push through sizers / no need for lubrisizer
- Doesn’t dry/melt/crack in long term storage
- Less or no smoke when shooting
- Easier cleaning
- No lead exposure when handling bullets
- Lower friction/ longer barrel life/ lower temperature (see American Eagle® Syntech™)
- Color coding projectiles (for different loadings with same bullet)
- They usually work in bullet feeders for your progressives
- You can enlarge dia of cast projectile by 0.002″ – 0.003″ – if you need!
- You can use soft alloy
- PC’d cast bullets can be used in supressors
- PC’d bullets will not clog compesators / ports
and if you just hate colours
- use CLEAR PC for traditional look (it has no pigment)
Fit PC isn’t the answer for all your problems (such as leading, tumbling..), you STILL need to fit your cast projectile to match your bores preferences. Fit is king – even with PC. It means you have to size your cast bullet to work best in your gun. But most importantly, don’t use undersized cast bullets.
Sizing Sizing BEFORE or AFTER PC’ing? It depends what dia. you want/need. Sometimes I size&attach GC and then PC. With tight fitting GC I must seat them first, then PC (and size again if necessary). Sometimes I PC first, then size to desired dia (9mm’s, .38/.357/.44).
Is your push through die scratching your bullets? It should not. Polish it.
Hammer test I call it hammer/vice test, because I use both. You pounded your freshly PC’d bullet with hammer and you squeezed another one in a vice and you have no flaking, or peeling of coating? Congratulations – your newly PC’d cast bullets passed the hammer/vice test!!
Lead in your barrel with PC bullets? You did your hammer test and you still have lead in your barrel? How much did you flare the mouth of your case? Did the mouth shave some PC off while seating the bullet? Not sure? Load a dummy round, disassemble it. Check.
Check also the diameter of that disassembled bullet, especially with a 9mm with its slightly tapered case. It could be that while pushing your bullets deep into the 9mm case, the case itself will swage down the base of the bullet. Remember that “FIT is king” and you have to use slightly oversize cast bullets. PC replaces lube, is alternative coating, helps you a lot – but it is not MAGIC.
Humidity is your enemy
An environment with low humidity that helps create static electricity is your friend when it comes to coating bullets. High humidity can turn your perfect coatings into “what the hell is wrong”. It happened to me in hot humid summer when it was raining. I was using some powders from UK and I just could not get good coverage – with same powders that worked well in dry cold winter. One solution was to take Smoke’s powders from their sealed container and after 3 years they worked as new.
To reduce humidity problems I have been PC indoors, in my basement. Try also preheating your bullets. Or just take everything (plastic container, bullets, powder) into air conditioned room and leave it there for 2 hours or even more. It helped me, so I could at least finish that problematic batch.
MP MOULDS for PC and Hi-Tek – alternative coatings
MP MOLDS has plenty of “alternative coatings” NLG (No Lube Groove) moulds. Don’t forget YOU CAN powder-coat ANY cast bullet with lube groove!
MP MOLDS is also making moulds with dia just for powder coating. One good example is Miha’s 357-135 FP Solid 8 cavity aluminium (a NLG PC variant of his famous 359-125 HP) which cast .357″ – perfect for PC. Final dia with PC is aprox .3585″, which means less sizing or no sizing at all. I size that bullet to .3575” and it works great in many 9mm pistols and even .38/.357 revolvers.
One of the best articles about PC with »how to« comes from well respected author, shooter, hunter, fellow caster – Jeff Tank Hoover, who was one of the first authors to write about advatages of PC. Here is a link to his articles.