Cheapest way to harden stick-ons

Nomadicone,

Magnum shot: It contains 3% to 8% antimony. 5% is maybe most common. Get the manufacturer's MSDS. Whatever it is, add about 2% tin to make it cast better, and it will make bullets. Probably a little harder than you want, but it will be heat treatable.

Antimony and lead don't cast well until you add a couple of percent tin. Get almost any lead-free plumbing solder to use as the tin source. I've yet to see zinc in a lead free plumbing solder (I've seen it in electrical solder once), but just to make sure it doesn't contain zinc, again, check the MSDS (usually available on line). Most all those solders are 95% tin, with the difference being bismuth, copper, antimony, selenium and other odds and ends. Don't worry about those unless one of them is zinc. Otherwise, just pretend the lead-free solder is pure tin. That's close enough to being true for bullet work. The other additives actually harden it a little further, though I think they are mainly to improve flow.

I'll mention that 16:1 lead tin is what Elmer Keith settled on in developing the .44 Magnum. BHN 11. It works well enough for most handgun purposes and is in your hardness range. It does not respond to heat treating.

Lyman #2 is 5% tin and 5% antimony and is about BHN 15. The 6% antimony 2% tin recipe is for Teracorp magnum alloy and it or something close to it is used by a lot of commercial casters. It runs around BHN 16, IIRC?
 
Note that the commercial 92-6-2 alloy is right at half linotype (84-12-4). So if you have a lot of linotype, you can make it into pistol alloy by combining it 50:50 with lead. The linotype casters will hate you for it, though.

Little as the hardening effect of tin is, the old Sharps Rifle Co. recommended 10:1 for Creedmoor bullets.

Greener recommended type metal for hard express rifle bullets... or mercury. Blend mercury into hot lead and it might be a question of whether the mercury poisoning or the dangerous game got you first.
 
Unclenick - I may not be understanding your first paragraph. I think you are suggesting using mag. shot with some tin added. I understand that but my problem is I have stick on weights that I need to harden to about BHN 12-13 I was hoping I could do it with mag shot but I have no clue what ratio to use. I have ot been able to find a source of Linotype near by and some have suggested 50/50 bar solder. I have found some of that now but thought it might make more sense to just pick up mag shot and add it 10/1 (or some ratio) to the stick-ons.

Jim - I am really considering linotype and a 50/50 mix with stick-ons but it appears I will have to have it shipped in rather than buy it locally.
 
Nomadicone,

My point was that some magnum shot has about the antimony levels you want in your finished alloy, while others have more. I understand it is manufactured using scrap in part, so the composition varies quite a bit. If you add pure lead from stick-ons it won't be as hard. You'll have to settle for a softer alloy. You could, for example, mix it 50:50 with lead and you may then have anywhere from 1.5% antimony, about like some swaged lead bullets to 4% antimony, about like wheel weights.

No matter what you do, you probably want to add 2% tin to make it fill in the mold well. If you use lead-free plumbing solder, just add 2% by weight. Close enough. If you use 50:50 solder add 4% by weight.

You probably need to consider investing in a Lee hardness tester to see exactly what you've wound up with. If it reads too hard, add more stick-ons. Too soft, add more shot. That kind of thing. The uncertainty of the compositions makes it impossible to present a definite solution.
 
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