.40 SW Optimum Hardness

[Krh1326]

Hi All …. HAPPY NEW YEAR!!

I am getting set to cast for a “new to me” cartridge.
.40 SW
I will be casting two different Lee 175 TC’s…
One traditional solid TC , and one “HollowPointMold” HP conversion.
Both will be powder coated and gas checked.
I expect them both to be in the 1000-1100 FPS range.

What would be optimal hardness for the solid?
What would be the softest , dependable hardness for the HP, for best chances of expansion?

Thank you all…
Ken

[Wheelguns 1961]

Are you powdercoating? I use 50/50 +2% tin in 9mm at around the same velocity, but they are powdercoated.

[lightman]

Something in the 10-12 BHN range should work fine. Powder coating will allow you to use a softer alloy.

[Krh1326]

Are you powdercoating? I use 50/50 +2% tin in 9mm at around the same velocity, but they are powdercoated.

Hi, yes powder coated ^ and gas checked.
You would use the same for both HP & solid?

[mehavey]

Hi, yes powder coated ^ and gas checked.Then I suggest you consider pure lead.

If it will feed reliably you have covered all the bases
-- including best probability some/possible expansion.

[Wheelguns 1961]

Hi, yes powder coated ^ and gas checked.
You would use the same for both HP & solid?

That is why I asked. With powdercoat and a gas check, you can easily use 50/50 +2% tin for both.

[Krh1326]

I thank you all. Happy New Year

[fredj338]

I dont think hardness is really an issue with gc & coated. I run pb coated 10-12bhn but only running maybe 1000fps. Btw, same thing for 9mm at 1100fps. Best exp with a lhp is no antimony, 20-1 lead/tin. If the hp is small/shallow, 25-1 works great to 1000fps.