How to make a brittle alloy?

[L1A1Rocker]

I'm wanting to come up with an alloy for a hollow point varmit round. How would one go about making their alloy brittle so that the hollow point shatters on impact? The bullet is a 30 cal 130gr at around 2000fps.

[garandsrus]

Use foundry type. It has more tin and antimony than linotype.

[madsenshooter]

The antimony content is what most determines the brittleness.

[MBTcustom]

cast them out of zinc and paper patch them?
I think you might be missing the point of cast boolits. Go with a wide flat nose and make them as soft as you can get away with. Think water balloon, not glass vase.

[L1A1Rocker]

Use foundry type. It has more tin and antimony than linotype.

I'll have to keep my eye out for "foundry type". I checked Rotometels and they have something called "super hard" that is 30/70 antimony / lead. If I cannot find any foundry type this could be a good option to mix 50/50 with pure lead and add a bit of tin to. Humm. . .

You wouldn't have a line on (or idea where to scavenge) foundry type would you?

[badbob454]

frangible bullets? or linotype foundry type and monotype maybe ... why?

p/s zinc brittle ? i know its hard but is it brittle ? i didnt think so ...

[btroj]

A relatively large HP on a 30 cal bullet cast from Linotype is going to be pretty brittle. The nose will likely break apart on impact with a portion of the base remaining intact to drive a bit deeper.
Try some alloys and see how they behave. I don't think you need to go super duper hard to get a HP to blow apart on impact.

[runfiverun]

bismuth and tin will shatter to dust on impact.
keep the tin in the 1% area.
or just do like the factory jaxketed guy's do, and use pure lead and a thin jaxket.
or forget the jaxket.
i can smoke a ground squirell or prairie dog with a swaged hollowpointed 22 cal boolit at 2400 fps.
if i hit with my 4/6/90 alloy it just zips right on through,unless i am using it in a larger caliber.
but the 44 mag is a bit much for dog hunting after the morning heats up.

[Good Cheer]

Something I've run into is a batch of lead pipe out of a chemical plant. The grain structure forms up and the liquid matrix holding the grains remains liquid through a comparatively wide range of temperatures. It is hard to mold with, smearing lead all over the sprue plate. The castings are softer than wheel weights but fragmenting on impact. Don't know what is in that pipe!

[largom]

A deep hollow point and 2000 fps with WW explodes on water jugs in my 30 cal. boolits.

Larry

[badgeredd]

2 pounds linotype added to 8 pounds COWW, water dropped with a deep hollow point works in my 6mm rifles, especially loaded up to over 2000 fps. By COWW, I mean sorted clip on WW only, no stick ons in the mix.

Edd

[sqlbullet]

3% antimony + 1% tin (for fillout). Drop them from the mold into water as hot as you can without a smear. They will be in the high twenties for hardness and will be brittle.

[onesonek]

3% antimony + 1% tin (for fillout). Drop them from the mold into water as hot as you can without a smear. They will be in the high twenties for hardness and will be brittle.

What?
Hard yes, brittle no. Not with that blend, i'm thinkin.

[runfiverun]

Something I've run into is a batch of lead pipe out of a chemical plant. The grain structure forms up and the liquid matrix holding the grains remains liquid through a comparatively wide range of temperatures. It is hard to mold with, smearing lead all over the sprue plate. The castings are softer than wheel weights but fragmenting on impact. Don't know what is in that pipe!

chemical pipe is 3-5% antimony but no tin.
it is extruded which is like swaging it,the same as hornady's swaged contains 5% antimony but is still soft.

[runfiverun]

3% antimony + 1% tin (for fillout). Drop them from the mold into water as hot as you can without a smear. They will be in the high twenties for hardness and will be brittle.

this will be hard but not brittle.
that's why we mix ww's with soft lead and waterdrop.
you get the benefits of the hardness to get it down the bbl,but you retain all the malleability of the original alloy.
bumping up the antimony to 4% and with 1.5% [waterdropped] i can poke little holes
though 12-16" pine logs with the 7mm at 100 yds easily and get the boolits back from the dirt behind it.
that made my mind up to not use that combination for deer hunting right off.

[williamwaco]

Many years ago, I did a lot of varmint hunting with the .357 Mag. At that time, max loads of 2400 would make a .358431 hollow point explode like a bomb. Varmints looked like they had been hit by a 75 grain hollowpoint from a .243.

These were cast from 100% clipon wheelweights and the hollowpoint was VERY deep.

These wheel weights are softer now so I am not sure it would work but I would try it.

If you need to experiment with alloys, you want to maximize antimony and minimize tin.

.