Mixing alloy for best 9mm

[Traffer]

Well I finally got my swaging die just right. It is a .357" round nose. I am going to swage some 124gn AFTER POWDRRCOATING. So I will have very nice concentric PC'd .357" boolits.
I molded up a couple hundred boolits to use thinking they were 13 BHN.
Turns out they are 20 BHN. Even if I could use them I don't want to. SO
When I melt them down again how much soft lead (6 Bhn) proportionally would I mix them with to get in the ballpark of 11 to 13 bhn?
And is 12 BHN an optimum hardness for PC'd 9 mm driven at moderate speeds?
Thanks
P.S. If it makes any difference I have a Norico 213 for the gun. Barrel slugs at .356" and the chamber is good.

[kevin c]

BHN mixing cross:

https://m.youtube.com/watch?v=7Y0raK6_Vbk

Dude's German or Austrian, and writes his numbers the way he was taught. I assure you his math is right, though assuming a linear relationship between boolit alloy hardness and component metal content isn't always. Still, as a first estimate, it'll get you in the ballpark.

At LASC, Fryxell's chapter on alloys suggests that a BHN of 12 is a pretty good all around alloy for up to magnum loads, and that's for standard lubes on cast. I'd guess a coated bullet that's sized right for your bore would do fine even if a bit softer.

[Traffer]

BHN mixing cross:

https://m.youtube.com/watch?v=7Y0raK6_Vbk

Dude's German or Austrian, and writes his numbers the way he was taught. I assure you his math is right, though assuming a linear relationship between boolit alloy hardness and component metal content isn't always. Still, as a first estimate, it'll get you in the ballpark.

At LASC, Fryxell's chapter on alloys suggests that a BHN of 12 is a pretty good all around alloy for up to magnum loads, and that's for standard lubes on cast. I'd guess a coated bullet that's sized right for your bore would do fine even if a bit softer.

Wow. What a great way to calculate alloy mixes. Thanks very much.

[jreidthompson1]

Looked quickly at his other English vids and this looked interesting, anyone know anything about it? Free quick load type software

https://youtu.be/8uWRwXPKg24



https://grtools.de/

Sent from my SM-N950U using Tapatalk

[kevin c]

The cross also works to give you proportions for mixing up new percentages of tin or antimony.

I don't do that kind of load development, so I don't know about the software.

[Conditor22]

I've found that when mixing tin with antimony you come up with a new alloy and have never found a formula that could accurately predict the hardness.

I would love to find a chart where someone has taken the time to mix a bunch of different combinations of tin/antimony/lead and posted the results.

I've got "bumpo's" calculator (which is great for getting you close), a similar calculator off of GB, and several other alloy charts.

This chart from LASC is helpful

[fredj338]

I run coated range scrap for my 9mm range loads, 130 PF. That is usually 9-10bhn. So 20 is getting close to lino. If you just want to extend the alloy, then 2-1, harder lead/harder alloy, it is easy to figure & mix. I don't know the bhn of that, don't really care, I know it is softer than 20, harder than pure or about range scrap. IF coating you should be fine. When alloying pure lead with lino I use 3-1 then water drop out of the PC oven.

[Traffer]

I think the hard stuff is this:
86.1% Lead
8.2% Antimony
5.7% Tin
I had some batches of alloy tested by BNE and "I Think" this was that one.
The alloy calculator that is floating around puts this at 18 BHN.
But this might be something different. I have about 15 very small batches of alloy most of which I cannot remember where they came from.
I don't want to just use it for alloying because of the high tin content. Maybe just add a little to batches of alloy that don't fill out well.