How to change the hardness of lead??

[Dadswickedammo]

So noob but done a good bit of ground work.
I have a bunch of lead eggs yeah found some egg shaped tins.
The lead consists of window weights roofing lead used bullets a few we.
Tossed it all in a big ol Pot and cast the eggs.
Seems soft I want to harden it up for .308 bullets. Maybe bnh 15+. What is it we are adding and where is the best value.
Thanx

[Baja_Traveler]

Get some linotype from Rotometals

[ioon44]

I get foundry type off flea-bay to harden alloy, just make sure it is in the original form.

[popper]

Rotometal superhard, cheapest way to go.

[John Boy]

The lead consists of window weights roofing lead used bullets a few we.
Tossed it all in a big ol Pot and cast the eggs.
Believe you might want to test the hardness before you start adding a harder alloy to get to Bhn 15

BTW - you have to be from the deep rural South - you write like a hillbilly!

[Soundguy]

I agree. test what you have, then go from there. As mentioned, super hard or lino can be added, depending on where you are at and what's in it, if it's not casting out great, adding some tin will help the mold fill out AND a little hardness. Rotometals has all these.

[Dadswickedammo]

Not a hillbilly! True Red neck!
And thank you for the info. I am just not at all familiar with linotype antimony run pewter. Ect
I have read a ton but till I see touch and use it just a lil unsure.
Thanx

[Soundguy]

Its just alloys of lead, antimony and tin.

I use lyman#2 for most of my boolit casting.

[RogerDat]

Antimony (Sb) is added to lead to make it harder, adds a lot of hardness but can make lead bullet brittle.
Tin (Sn) is added to lead in small quantity of 1% or 2% to improve how lead flows in mold and minor increase in hardness, makes lead bullet more flexible.

The two metals Sb and Sn also combine with each other in a lead alloy. In equal amounts the two improve things more than they would on their own. Sometimes called a balanced alloy Lyman #2 is 5% Sb and 5% Sn and has about 16 BHN hardness. For compare 6% Sb and 2% Sn is also about 16 BHN. So 1% Sb adds as much hardness as 3% Sn.

Early brass cartridges such as 45 colt the bullets were just lead and 5% tin which was strong enough to handle those low velocity rounds since the cases were loaded with black powder.

Printers lead such as Linotype, Foundry type, or Monotype have a lot of Sb and Sn so you can mix that in to softer lead to make it harder. Pewter has a lot of Sn, like 88 to 92 percent tin and can be found cheaply at garage sale and thrift stores so it is a common source of tin.

In this lead forum is a sticky on hardness testing with art pencils. The letter and number "rating" for pencils is actually a standard of hardness. By figuring out which art pencil can dig a groove in lead you know about how hard it is. Read that and use the lists in that to find your actual hardness.

Download the lead alloy calculator available for download also from a sticky in this forum. It allows you to enter weights of different types of lead and get the resulting hardness. If you don't have Microsoft Office you can download Apache Open Office for free and that can open the alloy calculator.

Advertising link at the top of the page to Rotometals leads to a foundry listing where you can buy lead alloys that are foundry pure. Or you can buy lead in the swapping and selling forum here. Rotometals is exact pure alloys, S&S forum is generally much less expensive than foundry, not as precise an alloy as a foundry.

You can even purchase exactly the alloy you need rather than mixing with what you have. That can be good approach at the start since it removes the lead as a variable when trying to load for something new.