What a mess!

[madsenshooter]

For over 10 years I been moving around 25lbs of an alloy, 70/30, Sb/Sn, or so I thought. Yesterday, for the first time, I tried to further harden some linotype as I wanted to try some bullets with a hardness around 26. Well 1.1 lbs of the alloy added to 7.7 lbs of lino increased the hardness from 19 to 21, far below what my calculations indicated it should. It appears either NEY or I (probably me) got the formula wrong, and what I have is 70/30, Sn/Sb. 11% tin makes really pretty silver, well filled out bullets! Cools real slow! I guess I'm in need of some antimony. Is this metal difficult to add? Does it require any special flux? Meanwhile, back at the drawing board....

[anachronism]

Why so hard? Bullets gat increasingly morebrittle as the hardness increases. Anyway, the answers for seek are here:

http://theantimonyman.com/

[madsenshooter]

It's one of those jacketed velocities with cast bullet experiments, so far gone wrong. But I'll put the batch in ingots and alloy it with something else sometime in the future. They would just be for target shooting, so brittleness wouldn't matter much as long as they'd survive the trip up the feed ramp and down the bore.

[runfiverun]

have you tried to water drop what you have or heat treat them.
i bet you could cut your lino in half, water drop them and hit 22 or better easily.
heat treating ww's [with arsenic] will get you over 25 up to 30 bhn and they can be tempered back down easily enough.

[madsenshooter]

Thanks for the suggestion, it's a windy day here in Northern IN, sucks the heat right outta my house, good day for experiments with the oven. I've been reading a little on heat treating and some say that heat treating works without the arsenic, though less efficiently. I have about 11% tin and about 12.5% antimony in them. Heat treating sounds as though it may be the way for me to go anyway, the ones I've cast so far are a bear to size and with heat treating I could size a softer as cast alloy before treating. I'll be trying it.

[leftiye]

Over 1/2% tin interferes with heat treating FWIW. Will still harden, but not as much. That's a lot of tin in there. I'd add it to wheelweights or pure to get a 2% tin 2% or more antimony solution, and then heat treat. Whole lot more useable alloy both in amount, and versatility that way.

[madsenshooter]

Wheelweights I have, but in a big chunk that I'll have to cut down with a torch to make some ingots I can get into my little pot. This is such a laugh, thought I had everything figured out when it came to making harder alloys with that 70/30, Sb/Sn. Would've worked great had it been in the proper proportions! I did try some of it before but didn't have a hardness tester. I thought it wasn't making things as hard as it should have! That was probably 5-6 years ago, I added some of it to wheelweights. Well, better go buy a couple propane tanks, that 15lb block of wheelweights isn't going to get up to the melting point easy.

[snowtigger]

I cut chunks of wheelweights or other bullet metal with a Skilsaw with a carbide blade. Wear eye protection, go slow. Works for me.

[TAWILDCATT]

what are you casting for rifle or pistol??if pistol you dont need heat treatment.and WW are plenty hard.:coffee:[smilie=1:

[madsenshooter]

Casting for rifles, a couple of Krags, a couple of T38 Arisakas, and a K31. I got the big blob of WW melted down, sacrificed a pyrex casserole dish and popped it in the oven. The Skilsaw was a good idea, closest thing I have is a hacksaw, I'd still be cutting. If I had money for a Skilsaw I'd buy jacketed bullets or another gun! The metal in that chunk was not very consistent in composition. The first ingots poured have a hardness of 11.8, the last ones came out grey with a crystalline lattice structure and a hardness of 14.3. Hard to tell what all was in it, leftovers from a couple teenagers casting experiments 40 odd years ago. Weird science this casting business.

[runfiverun]

i use a 4sn[tin] and 6 sb [antimony] mix for a lot of my rifle boolits.for about 18 bhn.
i do this if i need them a bit bigger. if the size is fine i water-drop ww's and 1% sn.
this gives an 18 bhn also.
a high tin content will make your boolits slump in the oven, watch your temps.
if/when i figure out this lube deal i have been doing i think i will try water-dropping the 4/6 mix
and see where it leads.

[357maximum]

A hydraulic log splitter makes short work of cutting up "CHUNKS"...[smilie=1: