My experiments with PC pistol and rifle bullets

fiver

Well-Known Member
mine looked just like Waco's with basically the exact same alloy [miner mixing variations and base stocks] but using different powders.
you could see through the P/C in places and it was a little splotchy-streaky in appearance.
 

wquiles

Well-Known Member
So in terms of cleaning the bullets before PC coating, remove any potential fingerprints/etc, if not acetone, what do you guys use instead?
 

Brad

Administrator
Staff member
I don’t clean mine at all. No lube ever gets on them in presizing so nothing to wash off.
So far no problems here. Humid summer days aren’t as easy to get a good coat but I just shake longer. I also am using no BBs.
 
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fiver

Well-Known Member
I'm pretty positive me and Waco's issue is the extra tin in the alloy.
the problem with moisture in the air is water carries a [I seem to recall] positive charge, this is what retards the attraction of the powder to the bullets.
I think [kind of my opinion maybe right maybe not] that Tin has the same affect but also lays down a very smooth coat on the surface of the bullets.
even when you get a slight frosty appearance you still end with the tin on the surface.
 

Ian

Notorious member
Fingerprints don't matter much. Shake the geezus out of them and the powder will stick. About one full minute of firm shaking like a percussion shaker, then hard as you can up and down about ten times, ending on a firm downstroke. Pull the lid and look to see how many bare "polka dots" the bullets have. If you see more than one or two on each bullet, repeat. If you start getting warts of clumped powder on the bullets, you used too much powder in the mix but a light shaking will knock most of them off. Humidity is never a problem for me and my shop gets nearly 100% like a sauna sometimes.

The way I do it, static electricity is less of the mechanism and embedding the powder into the bullet's surface is a lot more of the mechanism that gets it to stick. If I take a coated bullet and wipe off all the powder, the bullet's surface has a very fine bead-blasted look to it, like matte aluminum. The powder is abrasive and the hard shaking blasts off the surface oxide layer from the bullet and really makes a nice, textured surface for the powder to adhere.
 

Ian

Notorious member
even when you get a slight frosty appearance you still end with the tin on the surface.
Tin oxide, actually. That's the mechanism of tin in the alloy, it oxidizes instantly as the stream from the pot/ladle contacts air and protects the lead and antimony from forming oxide crystals on the surface. The tin oxide breaks and flows easily whereas the other metal oxides don't. Imagine lava flows where the surface cools and hardens into a thick crust that has to keep breaking up for the flow to move, same situation with filling a cavity and the more "soft" and flexible the surface oxide layer (tin), the better the fill out. The balanced alloy also has a finer grain structure on the surface under the oxide layer, so fewer nooks and crannies for the powder to get into and stick. Shake the hell out of the powder/bullets and use plastic BBs or beads to impinge the powder onto the surface.
 

Rick H

Well-Known Member
My basement in Michigan is humid 9 months of the year. I use the "shake the Bejesus" method of coating in a #5 plastic screw top container (Zip Lock brand) with plastic BB's. My powder sticks just fine. I don't worry about fingerprints nor do I wash my bullets before applying.
 
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wquiles

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OK, OK, I get the msg on cleaning before coating :rofl:

I plan on casting more bullets this weekend, and I will try it PC coating per you guys' advice :)
 

wquiles

Well-Known Member
OK, cast some fresh ones today. Unsorted pile:
10572


One of each of the ones casted today. Left-one has some history - being my very first mold, an old school LBT mold from 20-25 years ago :)
10573

Running some errands today - will update thread soon :)

Will
 

popper

Well-Known Member
I don't use tin in my alloys and still have trouble. Yes H2O has a slight positive charge. The inside of your bowl will also get rough and remove powder. Shaking up and down probably takes longer to roughen.
Metal tends to lose electrons when rubbed against #5 plastic - metal then (+), container and powder (-) which is good, except H2O is (+) so sticks to powder. Interestingly, glass is (+). Lead & copper are slightly (+), tin and zinc (++). Conclusion? tin and zinc should attract (-) powder better.
That the 041 in the middle? Almost looks like dirty alloy/ poor venting on the SIL.
 
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Brad

Administrator
Staff member
Water has a positive charge? Say what?
Water is polar but has no charge.
I think the humidity issues comes from two sources. Static doesn’t build as well when the air is humid and humid air leads to more clumping of the powder.
 

Brad

Administrator
Staff member
The water vapor in the air is quite different from tap water. Might be why Ian uses rain water to rinse his cases after wet tumbling.
 

fiver

Well-Known Member
I'm sure it is.
if I use just tap water the calcium leaves a sheen and makes the cases tarnish.
water softener? well at least the soap tries to make bubbles.

I use snow melt for water dropping and keep a couple of jugs of it on hand until the next winter.
 
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wquiles

Well-Known Member
Hope to try PC these (or a portion) tomorrow. For now, here are the 3x after visual sorting. Interestingly enough, I had a lower percentage of rejects out of the LBT mold, then the NOE mold, and the most rejects out of the 6x Lee mold:
10578


Sized the Ranch Dog 180's (Lee push through at .3099"):
10579

And the 180gr LBT (Lee push through at .3599"):
10581


Still need to size the Lee's ;)

Will
 

popper

Well-Known Member
Trivia - water is very interesting. Distilled is still ionozed but lack most tap contaminents. Steam boilers still need scaling reasonably often as do live steam piping. Rain water is as dirty as tap - takes dust to make clouds and rain drops collect on the dust. De-ionized water (the best stuff) is very expensive and an extremely aggressive cleaner. Used it to clean laser cavities. Being polar means it ionizes easily. I won't get into the isotopes of water.
Just cast, coat and size - works for me.
 

M3845708Bama

Active Member
Here is the latest batch of 30 cal rifle bullets:


Coverage is "OK", but not as good/even as with the pistol bullets:


Here are the pistol bullets after sizing for reference:



Feedback/suggestions/colors to try?

Will
Try putting on gas checks before powder coating. Try a little less powder or tap against side of bowl to knock off excess powder, makes a smoother coat also try extending cook time some!
 

358156 hp

Well-Known Member
it almost looks like the pigment 'fell out' of the powder or separated.
I get kind of the same thing if I try to use the powder a couple of times and it breaks down in the cup.
I started using [measuring out] just what I need and tossing anything leftover after a batch of bullets.
I've had this happen before. It does appear that it is possible for some powders to separate under repeated use. I had Smokes black do it to me. I'm basing this opinion on the appearance of the bullets, the bullets involved showed clear glossy coverage over the areas that didn't have much, if any coloring. This makes me believe that some (all?) powders consist of a pigment, and a clear carrier. In my case, I tossed out the powder that didn't cover, wiped out the shaking container, tossed the old BBs back in, and added fresh powder. The problem went away instantly. The situation recurred a couple of months later and I simply added a tsp. of fresh powder and everything worked well again. I suspect some powders may only tolerate so much shaking before they start to separate.

I also have a small amount of matte purple powder that doesn't tumble coat worth a hoot. I added some clear powder to it and got a sort of Lava Lamp like effect where it appears the two powders were incompatible of something. I'll get you some pics, they look pretty weird, but since I have full coverage from the clear, I'll go ahead and use up the bullets.
 

358156 hp

Well-Known Member
+1 'Bama.
I do this as well. I've found that the powder coat migrates in between the check and the bullet, making their relationship rather permanent. I've blown bullets up an steel target and found the gas checks on the ground with the lead "step" from the bullet still attached. Kinda cool!
 
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