#### daved20319

So Missouri Bullet Company has an informative page on their site that discusses "optimal" bullet hardness. I've read it before, but last night, a couple of things actually sank in . First, whoever wrote the page was mixing CUP and PSI, not an egregious error, but it leads to questions of competence. Further on, there's this slick little formula for determining "optimal" hardness, based on cartridge pressure divided by a constant, and yielding a BHN number. MBC happens to sell bullets in 2 different hardnesses, 12 and 18 BHN. Based on the formula, 18 is just right for full power .45 ACP loads. Problem is, using the same formula for 10mm pressure gives a BHN of 28. All of which begs a couple of questions.

First, is this formula for real, or just marketing hype? And second, if it is real, is it telling me I probably shouldn't be using cast lead bullets in the 10mm? BTW, the formula reads as follows:

Optimal BHN=Pressure(PSI)/(1422 x .90)

And finally, how hard can lead get, and if the formula is correct, can you get lead bullets up around 30 BHN? And does it really matter all that much? Thanks!

Dave

#### Capn Jack

If I can scratch it with my thumb nail it becomes round balls.

If I cant, it becomes bullets.

#### Longwalkhome

Over 1,000 fps and I use jackets, under 1,000 fps I use lead.

#### Capn Jack

I think big "D" is trying to differentiate between what hardness he should use for different speeds and types of cast bullets.

My standard for lead hardness varies pretty much depending on whether the projectile is patched, plain based, or gas checked and I've stopped shooting jacketed bullets in my .458 S as most of them cost almost \$1.00 ea.

Last Edited:

#### CLT65

Some people get really scientific about alloy and hardness. I don’t. I use mostly range scrap lead (fairly soft) and some linotype to mix with it for harder bullets.

I’ve found that hardness is important, but not as important as some make it out to be. What’s actually more important is bullet fit. Shooting undersized lead bullets through an oversized bore is going to cause trouble no matter how hard they are.

When the bullets are properly sized for the bore, hardness is not quite as important, and you can get a lot more velocity than you’d think. The old rule of 1,000 FPS for plain-base lead bullets goes completely out the window. I’ve loaded lots of bare lead bullets to 1600 fps with no leading. With gas-checked rifle bullets I’ve gone to about 2200 fps.

It even gets better with powder coating. Once I got good with powder coating bullets, I got rid of all my lube-sizers and traditional lube, and will never go back. I load lots of .44 magnum to 1400 fps, about 10/1 range scrap lead with linotype and a little extra tin, water dropped out of the powder coating oven. Never any leading.

I use Lyman #2 alloy for 44 Mag bullets, non-quenched. Their hardness, as I do not have a Brinell hardness checker, might be as high as 16 given the alloy.
I powder coat them and shoot at full power. I'll have to recover one next time to see what they look like.

#### dangerranger60

I don't claim to be an expert, But I base hardness more on velocity than on pressure. [I know pressure makes velocity].
Most pistol class bullets don't require very hard bullets. Most calibers even when pushed do just fine with a BH of around 12.
But things change when you go to calibers like .357 mag, .357 Sig, 38 super, and I have not tested it but 10 mm! For those I harden to about 18 BH. But to keep from shearing off the lead and leaving a smear of lead fouling you also have to make sure the bullet is fitted tightly to the bore!
I will also add this. Powder coating has let me shoot even softer lead without lead fouling. I powder coat rifle bullets which have a lot more velocity without having any of the fouling problems I had with lubed lead.
And the softer lead is both cheaper and easier to get! DR

#### daved20319

Thanks, guys, good info. When I use lead, it's always powder coated, I do enough damage to my brain with beer, I don't want to be adding potential lead poisoning . So it sounds like I really don't need to worry about 18 BHN in my 10mm, I'm anticipating loading 180 gr. between 1100 and 1200 FPS. This is mostly to save money, at at least a nickel per shot fired savings vs. the cheapest jacketed rounds, it adds up in a hurry. Later, and thanks again.

Dave

#### CLT65

I will also add this. Powder coating has let me shoot even softer lead without lead fouling. I powder coat rifle bullets which have a lot more velocity without having any of the fouling problems I had with lubed lead.
And the softer lead is both cheaper and easier to get!
Powder coating has been revolutionary for me. I have a couple different guns that I always had minor leading issues with, no matter what I tried (when using traditional lubed bullets). When I went to powder coating those problems vanished!

#### Certaindeaf

I'd consider the bhn 18 for hot 10 mm, 9mm etc. Lyman #2 is 16 and that has been in use for hotter loads for a long time.
Like has been said, powder coating is a game changer though as it performs much like a copper jacket at normal velocities when it comes to leading even with very soft bullets.

#### kmk1012

I do enough damage to my brain with beer
Buffalo Theory is all I have to say!!! Keep on Drinkin’

#### TM-Salem

When I first got into casting 11 or 12 years ago I bought into the optimal BHN for pressure and used to mix up alloy for a specific load pressure. I gave up on that when I shot my 11bhn 45-70 350gr cast and lubed bullets around 2000fps and no leading. I now cast EVERYTHING rifle and pistol at 11bhn and powder coat them. I just picked up a 30-06 that I have 170gr cast for that I will see how close to jacketed speed I can push them.

Now I just have to find some cheap 30-06 brass to load in.

#### CLT65

When I first got into casting 11 or 12 years ago I bought into the optimal BHN for pressure and used to mix up alloy for a specific load pressure. I gave up on that when I shot my 11bhn 45-70 350gr cast and lubed bullets around 2000fps and no leading. I now cast EVERYTHING rifle and pistol at 11bhn and powder coat them. I just picked up a 30-06 that I have 170gr cast for that I will see how close to jacketed speed I can push them.

Now I just have to find some cheap 30-06 brass to load in.
I've found that you can push them pretty darn fast with powder coating. You may not get leading, but (in my experience) accuracy tends to suffer unless you put a gas check on them. I have some 170gr powder-coat, gas check, 30-30 loads that are full velocity, and they shoot like a jacketed bullet.

Back when I first started casting, late '80s, I didn't know a thing or anyone who did. I read some manuals and probably misinterpreted half of what I read. The LEE instructions said to use 10/1 lead/tin, so I dutifully went down to the hardware store and bought a pound of solder. Those were probably the most expensive bullets I ever made! I found out pretty quick that wheel weights work just fine, and 10% tin is an absurd waste. I think LEE still recommends that, and I don't understand why. It seems flat-out stupid to me.

I have a bunch of 30-06 brass. If you ever get up to McMinnville let me know.

#### oremike

I know if the bullets are too hard when you shoot steel they shatter into sharp shards and can ricochet back into the fireing line and if the are soft they splat but stay in one piece then fall to the ground right under the plates. Everyone has picked up a quarter size lead blob, that's soft enough.

#### TM-Salem

I've found that you can push them pretty darn fast with powder coating. You may not get leading, but (in my experience) accuracy tends to suffer unless you put a gas check on them. I have some 170gr powder-coat, gas check, 30-30 loads that are full velocity, and they shoot like a jacketed bullet.

Back when I first started casting, late '80s, I didn't know a thing or anyone who did. I read some manuals and probably misinterpreted half of what I read. The LEE instructions said to use 10/1 lead/tin, so I dutifully went down to the hardware store and bought a pound of solder. Those were probably the most expensive bullets I ever made! I found out pretty quick that wheel weights work just fine, and 10% tin is an absurd waste. I think LEE still recommends that, and I don't understand why. It seems flat-out stupid to me.

I have a bunch of 30-06 brass. If you ever get up to McMinnville let me know.

CLT65,
I gas check all rifle bullets so no issues there, I borrowed a mold from Conditor22 and cast a couple thousand 170gr gas check bullets knowing that someday I would get a 30-06, that day has come.. I got my 30cal aluminum GC's in from Sage 4 days ago so I am now putting them on.

How much 30-06 brass do you have and how much are you wanting for them?
The wifes aunt and uncle live in Willamina and we go see them a couple times a month so its pretty close.
Tim

#### CLT65

If you just want a few and don't mind mixed headstamps (including GI) and not all once-fired, I've got probably 30-50 pieces that you're welcome to for free. It's still very usable brass.

I have a bunch of nicer brass too. I probably have some that's surplus to my needs, that I'd sell reasonably if you wanted more. Send me a PM when you're headed this way.

### Upcoming Events

Oregon Arms Collectors September Show
Portland, OR
Rimfire Challenge Oct 9th @ DRRC
Eagle Creek, OR