Powder coating question.

[Casull]

When I saw the 30 number I became curious. I have no idea of the number of pounds of #4 Babbitt metal I melted and Lourdes for rope sockets on pump jack bridles but it was a lot. I got the bright idea of casting round balls to use in my muzzle loading rifle using it. They made beautiful ball and were pretty accurate to boot. I did have to use a thinner patch because they wouldn’t engrave at all. I could recover those I shot into a sandbank and found no expansion all. You could wipe them off and reuse them if you wanted. They were so hard that they shattered on any rock I shot. I went agoogling to find the hardness of #4 Babbitt and finally found a website that gave bar metal at 23 which is what I used. Bearing Babbitt only made it to 29. I’m leery of the 30 hardness and even if it could be achieved it would be like FMJ and I would be leery of shooting it unless sized the same as jacketed bullets. The bar Babbitt is so hard it makes a “clink” sound when tapped with a hammer.

i made them 30 bhn because of my quest to successfully heat treat, i went weeks not being able to get ANY results at all. then i found out it was my homemade **** alloy that was the problem. being new and more absorbent then a shamie i fell for the lee test kit chart and that says that if i wanted to cast my own bullet for a near max load 454 casull i would need BHN of well...... its off the chart. A max 454 load is 65,000 psi and the chart stops at 46,900 with a BHN of 36.6 soooo. i know that powder coating and a gas check will lower the bhn requirement i need but haven't figured out by how much yet.

 

[Casull]

Perhaps a silly question, but was the coated lead tested after the coating was scraped off? Otherwise it is the hardness of the coating which is being tested...

the base of the bullet wasn't coated. i tested after heat treating and after PC cooking

 

[Casull]

Why not just try it with 10. Smash them and let us know. That's an easy test...

Im on it capt'n

 

[ms6852]

Get an oven thermometer to confirm that the temperature settings on the oven dial are accurate. If not, bake a single bullet at different temperatures and times and do a smash test. Oh, don't forget to write down the temps and time for each bullet. Whenever the bullet is smashed and the powder coating does not flake off use that temperature and duration of time for the rest of them. It can be tedious at the beginning but once you have it pegged you know what setting will work on or oven or toaster.

 

[Casull]

Get an oven thermometer to confirm that the temperature settings on the oven dial are accurate. If not, bake a single bullet at different temperatures and times and do a smash test. Oh, don't forget to write down the temps and time for each bullet. Whenever the bullet is smashed and the powder coating does not flake off use that temperature and duration of time for the rest of them. It can be tedious at the beginning but once you have it pegged you know what setting will work on or oven or toaster.

I learned last night that Prizmatic powders offers a high heat powder coating. So i may be able to heat treat and bake in the same step. Im going to call them today once they open.

 

[Casull]

Im on it capt'n

This test is only valid with this specific bullet size and shape. A larger bullet will not respond to heat treating the same as a smaller bullet. A smaller bullet will reach slump temp much faster then a large one. That being said the BHN’s on this chart using a larger bullet will probably respond differently using a smaller bullet, for instance the bullet used here started annealing back to the original hardness at 300 for 20 mins. A smaller bullet will reach annealing temp much faster. Im currently chasing a lead on a powder coat that needs less then 300 F to cure and that could mean its possible to heat treat then cure powder coating without any BHN loss, if its tough enough .

 

[AJC1]

What a great test all kinds of good data. It appears your hardness is still way low. Any runs at the 1 hour needed for hardness.

 

[Casull]

Get an oven thermometer to confirm that the temperature settings on the oven dial are accurate. If not, bake a single bullet at different temperatures and times and do a smash test. Oh, don't forget to write down the temps and time for each bullet. Whenever the bullet is smashed and the powder coating does not flake off use that temperature and duration of time for the rest of them. It can be tedious at the beginning but once you have it pegged you know what setting will work on or oven or toaster.

Im going to go full bore and bake it at 500 for 1 hour to see what happens. If that doesent work then this type of coating isnt right for my application. I talked to the pros and they said if i rais the temp slowly it should be fine witch i didnt i pre heated the oven.

 

[Casull]

What a great test all kinds of good data. It appears your hardness is still way low. Any runs at the 1 hour needed for hardness.

Im going to approach it a little differently, im going to try 490 for 1 hour. I talked to the pros and they said to slowly ramp up the temp for best adhesion, I pre heated the oven. Ill do a crazy smash job too for max testing results. The pros are going to call me back with the best product for what im trying to do. If slower ramp temp helps then the 500 for 30 mins may hold up better even at 1 hour.

 

[Casull]

View attachment 921184
This test is only valid with this specific bullet size and shape. A larger bullet will not respond to heat treating the same as a smaller bullet. A smaller bullet will reach slump temp much faster then a large one. That being said the BHN’s on this chart using a larger bullet will probably respond differently using a smaller bullet, for instance the bullet used here started annealing back to the original hardness at 300 for 20 mins. A smaller bullet will reach annealing temp much faster. Im currently chasing a lead on a powder coat that needs less then 300 F to cure and that could mean its possible to heat treat then cure powder coating without any BHN loss, if its tough enoughView attachment 921184 .

*update flash cooking will not work because the coating needs time to bond to the surface.

 

[ms6852]

View attachment 921184
This test is only valid with this specific bullet size and shape. A larger bullet will not respond to heat treating the same as a smaller bullet. A smaller bullet will reach slump temp much faster then a large one. That being said the BHN’s on this chart using a larger bullet will probably respond differently using a smaller bullet, for instance the bullet used here started annealing back to the original hardness at 300 for 20 mins. A smaller bullet will reach annealing temp much faster. Im currently chasing a lead on a powder coat that needs less then 300 F to cure and that could mean its possible to heat treat then cure powder coating without any BHN loss, if its tough enoughView attachment 921184 .

This is great info, thanks for posting it.

 

[rsrocket1]

I think you need to go back to square one and ask yourself why do I have to have a 30 BHN bullet for XX pressure and XX velocity?
Prior to powder coating, have you noticed flyers with softer gas checked bullets with adequate lube? If so, then perhaps your bullets are slumping and you do need a higher BHN.
Are you experiencing leading with PC bullets at high pressures and velocities? If not and your bullets aren't slumping, why do you need high BHN bullets?
I don't even test the BHN of my bullets anymore but I can get 1-2" accuracy @100 yards out of my Lee C309-113-F bullets at 1800 fps. That's only 16 kspi peak but I regularly shoot the Lee 356-120-TC out of my 9mm guns at 35 kpsi and they work fine too.

Rather than try for "unreachable" BHN's, see if what you already have works?

I also read that it takes a couple of weeks to stabilize hardness. Did you test your 28 BHN bullets a couple months after casting and did you test your 12.5 BHN bullets long after powder coating? I also take it that you are cutting away at the powder coating to test the hardness of the actual lead and not testing the hardness of just the coating itself. Sorry if I missed it.

 

[AJC1]

I think you need to go back to square one and ask yourself why do I have to have a 30 BHN bullet for XX pressure and XX velocity?
Prior to powder coating, have you noticed flyers with softer gas checked bullets with adequate lube? If so, then perhaps your bullets are slumping and you do need a higher BHN.
Are you experiencing leading with PC bullets at high pressures and velocities? If not and your bullets aren't slumping, why do you need high BHN bullets?
I don't even test the BHN of my bullets anymore but I can get 1-2" accuracy @100 yards out of my Lee C309-113-F bullets at 1800 fps. That's only 16 kspi peak but I regularly shoot the Lee 356-120-TC out of my 9mm guns at 35 kpsi and they work fine too.

Rather than try for "unreachable" BHN's, see if what you already have works?

I also read that it takes a couple of weeks to stabilize hardness. Did you test your 28 BHN bullets a couple months after casting and did you test your 12.5 BHN bullets long after powder coating? I also take it that you are cutting away at the powder coating to test the hardness of the actual lead and not testing the hardness of just the coating itself. Sorry if I missed it.

He is trying to control these factors for understanding. I started off asking the same questions. It's a skillset he desires.

 

[Iwsbull]

I have been running straight air cooled and powdercoated gas checked in my Casull and have pushed them pretty hard with H110 with good accuracy and a clean bore. They are from the MP 45-340 mold. Weighing in at 343 for solids, 329 for the penta and 324 for the large hp. So far I have only loaded the penta but just tonight I coated and checked some of the solids and large hp to play with The biggest thing I will say is be careful when using the minimum load data of H110 as that is the only squib I ever had.

4B1A9890-C41E-4041-8120-8ED240488BA2

• Iwsbull
• Jun 5, 2020

Mp 45-340

 

[Casull]

He is trying to control these factors for understanding. I started off asking the same questions. It's a skillset he desires.

this is exactly right. i made an alloy that would not heat treat at all and that started my quest to figure out why, well i never did figure it out so i started making a cww alloy because that will respond to treating then i read the lee hardness test kit reference sheet and it said i would need a bullet of like 40 bhn to shoot at 45,ooo psi. Well thats BS it only needs to be about 18. but the learning and testing didn't seem to stop. As of last night i heat treated and cured powder coat in the same step. I heat treated the powder coat at 490 for 1 hr and the powder coat actually looks good so in a couple more days ill know if it hardened to 30 and cured the coat properly all in one step with no hardness loss. That would mean people can use cheaper softer lead to get the same hardness as before plus the benefits of powder coating. I also have a company testing new powder coat resins that work better curing at higher temps se people can eliminate the need for this two step process.

 

[Casull]

Good info i have the same powder so ill keep this in mind.

 

[Casull]

I think you need to go back to square one and ask yourself why do I have to have a 30 BHN bullet for XX pressure and XX velocity?
Prior to powder coating, have you noticed flyers with softer gas checked bullets with adequate lube? If so, then perhaps your bullets are slumping and you do need a higher BHN.
Are you experiencing leading with PC bullets at high pressures and velocities? If not and your bullets aren't slumping, why do you need high BHN bullets?
I don't even test the BHN of my bullets anymore but I can get 1-2" accuracy @100 yards out of my Lee C309-113-F bullets at 1800 fps. That's only 16 kspi peak but I regularly shoot the Lee 356-120-TC out of my 9mm guns at 35 kpsi and they work fine too.

Rather than try for "unreachable" BHN's, see if what you already have works?

I also read that it takes a couple of weeks to stabilize hardness. Did you test your 28 BHN bullets a couple months after casting and did you test your 12.5 BHN bullets long after powder coating? I also take it that you are cutting away at the powder coating to test the hardness of the actual lead and not testing the hardness of just the coating itself. Sorry if I missed it.

other people said it was possible and i proved them right by successfully treating cww to 27.2 after two weeks. I dont need high BHN bullets "TO SHOOT" i need high bhn bullets as a result and a result only. I have know one in my pocket to ask questions if i need to so i took control and did my own testing to get my own answers. Im putting in the time and learning hardening curves cure temp curves annealing curves. why? because maybe someone will need help with something and maybe i would be able to help them understand why what they are doing inst working out. because that's what i needed and had trouble getting until AJC1, texas10, tightgroup tiger, and a few other awesome people who's names are slipping me walked me through a few things
.