Cast Bullet Hardness

[BaltimoreBoy]

As so many have before me, I am going to embark on reloading with 38/357 – handguns and carbine.

Over the years, I have shot various jacketed rounds almost exclusively.

I had initially thought that I would simply use jacketed bullets, but on reflection it seems I would be missing a bet if I ignored lead, but I don't think I understand lead sufficiently.

I have read the Missouri Bullet website blurb on hardness and what causes leading and it seems reasonable – it also seems to mesh with people's experience to judge from the various posts I see.

From what I see on the MB site, it appears that MB bullets are a bit to a lot softer than some of their competitors. Typically about 18 numbers Brinnell for .357 and about 12 for 38 spl. and they seemed to imply that many manufacturers run about 24.

My question is this: If one is loading for higher velocities in .357 (using say 158 or 180 gr) are there any disadvantages to using 18 BHN lead?

Disadvantages could be during manufacture, clean up, or actual use (say as a trail gun to handle black bear.)

(Oh and a parenthetical question – what does “hard cast” mean? Is it something that is defined, or is it just 'way harder than regular lead'?)

 

[rcmodel]

Many moons ago, in black powder days, all factory lead bullets were very soft, and almost pure lead with a very little tin added to make them cast better.
Probably about 7 - 8 BNH hardness.

Then came Phil Sharp and the .357 Magnum, Elmer Keith and the .44 Magnum, and other early exterminators working to improve revolver performance.

Soon, they found they needed a harder bullet to withstand Magnum level pressure & velocity.

More tin was added to make them harder.
Thus, "hard Cast" became a term used to describe them.

But the fact of the matter is, Elmer & Phil's "hard cast" Magnum bullets were generally made from 1 part tin to 16 parts lead.

That gives a BNH of about 11!!!

If they wanted a really hard bullet for maximum big game penetration with no chance of shattering on bone, they might have used something similar to Lyman #2 alloy.
That is 90% lead, 5% Tin, and 5% Antimony.
And it gives a BNH of about 15.

Today, most commercial casters use something like 92% Lead, 6% Antimony, and 2% Tin.
That gives a good looking bullet that falls out of auto-casting machine molds like jelly beans.
And that gives a BNH of 18 to 20.

Which IMO, is way too hard for most general use shooting.

rc

 

[smurf hunter]

Slightly off topic, but I have only great things to say about Missouri Bullet. Their shipping is incredibly fast and cheap considering.

I've loaded some 10 BHN that did not lead, and 20 BHN that did. I think the charge has as much to do with it as the bullet.

Usually when I'm working up a new load, I'll do batches of 5 (progressively hotter charges for example). After my range trip, if I discover leading, it's difficult to determine if there was a specific load that caused it or all of them.

Honestly it's rare that I see leading problems with their bullet - regardless if it's a light cowboy load, or something for Harry Callahan.

 

[Blue68f100]

The fit to barrel is key in avoiding leading. As well as powder/burn rate and even lube makes a difference. I've used hard to soft, and it all works if you want to spend the time to make it work. Another option is just add a gas check, but then you adding another few cent and time to the process. But it allows you to push a soft bullet hard so you can get good expansion.

I don't know what kind of velocities you are shooting for, but once you get over 1400fps it hard to stop leading.

 

[Jesse Heywood]

It's all in the fit to the bore and the pressure. l have pushed Brad's 357 Action to 1,200 fps and over 30,000 cup without leading. I have also shot his 12 BHN bullets at low 38 spl. velocity and pressure without leading. With MBC you get consistency and a great lube. I haven't had that good of results with home cast bullets, but we're working on the mixtures.