How does PC coating Change Bullet BHN?

JWFilips

Well-Known Member
I like my bullets soft (BHN 10) for CC..... Now with PC coating how much harder do they become and is there anyway of measuring it?
 

gman

Well-Known Member
The coating itself may be hard but I have not found any difference in BHN when testing PC'd bullets on my cabine tree. I've shot quite a bit of 12 BHN coated bullets out of my 44 magnums and 357 maximums at full throttle loads.
 

Ian

Notorious member
The bullets may actually not be as "hard" after baking and air cooling as they would otherwise be air-cooled from the mould. The coating seems to slow the transfer of heat to the air during the critical transition phase of cooling which establishes that the final toughness of the alloy will be after a few days/weeks when the dendrites settle in and the precipitation hardening occurs.

I read somewhere that someone tested the polymer itself at something around 30 BHN which I have no trouble believing.
 

JWFilips

Well-Known Member
I read somewhere that someone tested the polymer itself at something around 30 BHN which I have no trouble believing.
So In Essence A BHN 10 Bullet could have a 30 BHN shell around it ? Would that render that Bullet at 30 BHN on impact vs 10 BNH in an non PC coated bullet?
 

Ian

Notorious member
The coating has little effect on anything once the bullet is outside the gun and provides no significant jacket strength to the bullet upon impact. Hit the coated bullet with a hammer and you can easily see how it behaves. You still have a 10 bhn bullet but it might penetrate a little better owing to the slick coating.
 

Rockydoc

Active Member
So, is BHN only important in internal ballistics and terminal performance in the target game animal? When the bullet is in the barrel and in the tissue.
 

Bret4207

Northern NY
So, is BHN only important in internal ballistics and terminal performance in the target game animal? When the bullet is in the barrel and in the tissue.

Whoa! What question! Let me get a big bag of popcorn and watch the opinion fly on that one! IMO, sorta, kinda, maybe, sometimes...or not.
 

CWLONGSHOT

Residing in New England
The answer is a resounding NO!

It is a COATING UPON THE BULLET.

Now the PROCESS many use heating and quenching surely CAN HAVE an effect.

The Coating it self can be pretty strong andis likely pretty "hard" in some Formulations. But I have not found appreciable effects from my PC.

I know I cannot test a bullets hardness thru PC...

One of my favorites is 20:1 powder coated for HP hand gun bullets. Its a very reliable and repeatable expander @ 1200 fps. Large HP or overly small cavities change that a little.

ACWW are also a very reliable expander at 1650 ish fps. Med small HP of the Gould Express is where I have learned most with this alloy.

CW
 
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Wolfman

New Member
Most of us use polyester powdercoat. It has a hardness of 26-28 BHN. Unlike a copper jacket it is flexible. I have heard that powder coat forms a poly jacket around the bullet. It forms around the bullet but I don't know if it performs like copper. That is what we are trying to do,get a jacket that performs as good as copper.
 

bruce381

Member
thats kinda the point with powder coat is you can run a soft bullet with no leading at high speed and still get expansion.
Ian is expert here I still use a star with carnuba red.
 

CWLONGSHOT

Residing in New England
:p
thats kinda the point with powder coat is you can run a soft bullet with no leading at high speed and still get expansion.
Ian is expert here I still use a star with carnuba red.
100% YES!

I have shot some soft for a hand gun in my rifles to 2200 fps with out any bullet Fouling! Makes using expanding bullets much more effective. (Well easier at lower Velocities)
 

John

Active Member
So, is BHN only important in internal ballistics and terminal performance in the target game animal? When the bullet is in the barrel and in the tissue.
If I take this literally there is no difference in effect with a properly lubed and a properly powder coated bullet from the point they exit the bbl to impact of target. Yaw, tipping, wind action, flight time, going to sleep, and drop should all be in all practical purposes, equal regardless of either element.
 

Reloader762

Active Member
My observations on cast bullet air cooled or quenched from the mold and how the curing process will anneal or harden the cast lead bullets using an alloy that responds to water quenching or heat treating. Your results may vary depending on the original alloy used and the as cast BHN and at the time the bullets BHN is tested.

1. If you air cool your bullets when cast then PC them and allow them to air cool again the second time there is no noticeable change in the as cast BHN of the bullet.

2. If you air cool your bullets when cast then PC them and quench them right out of the toaster oven they will gain a hardness of about 75% over the as cast BHN.

3. If you quench your bullets out of the mold to begin with then PC them and allow them to air cool they will soften around 50% from the original first quenching BHN.

4. If you quench your bullets out of the mold to begin with then PC them and quench them right out of the toaster oven a second time you only loose around 15% hardness from the first quenching. This is due to the time and temperature of the bullet as it's cured in the toaster oven vs. just quenching out of the mold or heat treating the bullet using a longer time and temperature.

All my handgun and rifle bullets get powder coated and have been for a few years now. I basically run two alloys, for bullets usually HP's in all my handgun calibers where velocity will not exceed over 1100 fps. I use two part lead to one part COWW with a pinch of tin, for everything else the alloy is a 50/50 mix of pure lead / COWW with a pinch of tin. Air cooled the 50/50 mix works great for 357 mag. HP's for all other none expanding pistol or rifle bullets I water quench the bullets out of the toaster oven size and gas check as needed and let them sit for several weeks.
 

SW Lever

New Member
In my experience, wheelwright bullets water dropped go about 19.9. BHN(LEE Hardness tester). PC them at 400 degrees, 20 mins. File a flat per instructions and test just like Normal on shiny lead removes PC. And I get 14.9 BHN Suits me. Your results may differ. Oh, forgot, added about 3 Oz 60/40 solder to melt.
 

CWLONGSHOT

Residing in New England
In my experience, wheelwright bullets water dropped go about 19.9. BHN(LEE Hardness tester). PC them at 400 degrees, 20 mins. File a flat per instructions and test just like Normal on shiny lead removes PC. And I get 14.9 BHN Suits me. Your results may differ. Oh, forgot, added about 3 Oz 60/40 solder to melt.
Your experience mirrors the chart above. Remember COWW are not a controlled substance. Meaning THEY AINT ALL EXACTLY THE SAME!! :embarrassed::rofl::headscratch: