BHN after powder coating

[MR CHEN]

Will the powder coating process (400*for 20 min) soften the bullet alloy.
If so, is there a rule of thumb, or do you have to test?
My alloy is 9.5lbs coww and 0.5 lb of 60/40 soldier. According to bumpo628s calculator it should be a bhn of 12.2. Don't want to go any softer or harder.

[mehavey]

If you're normally air-cooling (vice water drop), no appreciable effect.

FWIW: I wouldn't rely any any alloy "calculator"
Get a Lyman BHN tester and get a measured number.

[la5676]

I'll post a really silly kweshun here, as I'm new to PC. I've never shot anything but straight COWW on pistols with the old traditional lube, always some mix of lino and COWW for rifles. I'm going the PC route now for all my pistol shooting. Question is, if the PC is providing a "jacket" more or less, is the BHN really that much of an issue anymore. The lead never comes into contact with the rifling (if your PC coating is good). Obturation is obtained easier with softer lead not driving so hard. Is there another factor at play here with the PC method different from the old 45-45-10 lube method? Curious minds need to know.

[JonB_in_Glencoe]

Will the powder coating process (400*for 20 min) soften the bullet alloy.
If so, is there a rule of thumb, or do you have to test?
My alloy is 9.5lbs coww and 0.5 lb of 60/40 soldier. According to bumpo628s calculator it should be a bhn of 12.2. Don't want to go any softer or harder.

PC process (bake@400º) will anneal or partially anneal your alloy.

[JonB_in_Glencoe]

I'll post a really silly kweshun here, as I'm new to PC. I've never shot anything but straight COWW on pistols with the old traditional lube, always some mix of lino and COWW for rifles. I'm going the PC route now for all my pistol shooting. Question is, if the PC is providing a "jacket" more or less, is the BHN really that much of an issue anymore. The lead never comes into contact with the rifling (if your PC coating is good). Obturation is obtained easier with softer lead not driving so hard. Is there another factor at play here with the PC method different from the old 45-45-10 lube method? Curious minds need to know.

PC is not a jacket, it is a lube.
Everything that applies to a Rifle load and Bhn, still applies.

[cwlongshot]

PC is not a jacket, it is a lube.
Everything that applies to a Rifle load and Bhn, still applies.

.

I beg to differ. A powder coat properly applied is a “jacket” by all definitions I’m aware.

I have done my own tests and continue to see reduction to hardness from powder coated bullets that are not quenched in water out of the oven.

CW

[fcvan]

The PC ‘jacket’ does not act the same as copper as it is very thin and takes less to disrupt the coating. However, that thin layer is very tough, very slick, and does operate like a jacket. Certain semiautomatic cartridges suffer damage during cycling but not so when coated with PC.

I have a 9 mm AR15 that hates anything not round nosed, including RF and TC. It feeds RN all day long without deformation, whereas even plain lubed RN even shows mild deformation. Where I am really seeing some promise is with 223 Rem using a PB boolits. I still need to sweeten the alloy a tad in hopes of tightening groups, but my usual pistol lead is doing well at 2250-2450 FPS depending on barrel length. More testing is needed there, but 223, 308, and 30-06 are fantastic with same alloy, 2250 FPS, and gas check. The PC coating leaves nothing behind but gunpowder residue.

[cwlongshot]

Properly applied PC stays on!

CW

[Conditor22]

PC is an elastomeric polymer coating (polyester) that functions as a lube

[Silvercreek Farmer]

PC is an elastomeric polymer coating (polyester) that functions as a lube

Nice chart! Any chance you have or could do COWW mixed with pure? Say maybe 50/50?

[la5676]

I do enjoy reading and picking up any and all info on this site, but at times I have to shake my head and say what the heck. In the chart above, I see it helps boolit hardness to water quench after PC. In my many hours of bingeing on youtube PC videos, I watched more than a few recommending water or ice water quenching right out of the oven. Not a few days ago, I just read on this forum (and I couldn't locate the thread now if my life depended on it) that one needs to let the PC cool down slowly to cure properly, or I assume it will get brittle. Just when a guy thinks he has a handle on things, he reads some more and gets confuseder.

[MR CHEN]

If you're normally air-cooling (vice water drop), no appreciable effect.

FWIW: I wouldn't rely any any alloy "calculator"
Get a Lyman BHN tester and get a measured number.

I'm going to get a tester.

[MR CHEN]

It looks like I have 4 that say no (will not soften) 1 yes, and five off topic.

[la5676]

It looks like I have 4 that say no (will not soften) 1 yes, and five off topic.

I'd really like to find the comments I referenced above and put them here too. But, I think you made the right choice, get your own tool.

[Conditor22]

It looks like I have 4 that say no (will not soften) 1 yes, and five off-topic.

unfortunately this is getting to be the norm

[bmortell]

im sure going from air cooled to pc cooked and air-cooled is technically different but less than anything your gonna notice or even measure maybe

[Gohon]

PC process (bake@400º) will anneal or partially anneal your alloy.

Only if the casts were water dropped after casting. The BHN of a alloy cannot go below it's original state. So if your casts were air cooled and came out at 12.2 then 12.2 is as low as the BHN will go after baking powder coating.

[barnabus]

unfortunately this is getting to be the norm

that's why I dismiss over half of what the experts say on here

[la5676]

that's why I dismiss over half of what the experts say on here

Bizzactly.

[Dimner]

PC is an elastomeric polymer coating (polyester) that functions as a lube

I might not be adding to the conversation. But a HUGE thank you for this chart.