Bismuth and Tin use for....what?

[RogerDat]

I had a chance to pick up some bismuth and tin (Bi 53/ Sn 47) alloy. My first thought was it would be useful to get 2% tin into a casting alloy and thought I recalled bismuth was used for lead free bullet casting so the 2% of that getting added with the tin probably wouldn't be a problem.

More reading has me wondering if maybe this alloy would be more useful if used as is or in other ways. I see people using and Rotometals selling Bi 88% Sn 12% for lead free bullet casting and have read where people are going up to 20% tin or so to get a bismuth bullet that doesn't break apart. Also for waterfowl shot, although not sure how one would cast for many of the sizes used for duck or geese hunting.

Cast for fishing weights is one use, I don't do it but people do. Or cast as round ball as some expensive lead free slingshot ammo. Don't know if it could be used as is for California hunting ammo or if it would just be too light weight with that much tin.

Looking for ideas of what I should do with what seems like a pretty rich alloy. Considering the price of the stuff I would hate to waste it.

[lightman]

I would be afraid of the Bismuth. If you try it please let us know how it works.

[Harter66]

Bismuth was the first alternative to steel for non-toxic shot .
Bismuth is the active ingredient in Pepto Bismal .
In the first shot alloy it was too hard and had a bad tendency to crush up and stay in the wads . That was as memory fails me a 5-7% tin alloy more tin was added , to about the alloy you have maybe as much as 15% . The density value of the alloy was lost dropping from 95% to only 90% for the shot . It was then feed on steel components with lead shot counts in the realm of 1425 fps . With the tin values raised the shot was much less brittle and very much improved . It was very useable in sizes from #6-2 for fowl .

I think the 12% alloy based on shot experience and several California threads with hohum success , would be good in "square" bullets . Meaning bullets of 1.5 dia or less in length . The move into 3+ diameters in length I think will result in fractured bullets unless the tin values are raised even higher . Of course that's a mechanical speculation without any science values to back it up .

The Bismuth is going to be very hard but not terribly shear resistant past its initial engagement .

[country gent]

Bismuth has been used for heavy lead free shot. I believe bismuth is denser than lead so bullets and shot would be heavier for a given size. Tin and or a very small amount of silver may help adjust weight and flow of the material.
Another consideration is how much did you acquire 0-10 lbs or so wouldn't be but a short run of bullets or shot using it to alloy it will go a lot farther and may be more useful. 20lbs up may justify runs of bullets shot as that's enough to use for awhile.

I wonder of the guys casting using reclaimed shot from ranges how much is bismuth being mixed in with the lead antimony shot. As it becomes more popular this may go up to a point where problems may show

[dondiego]

I have used bismuth in shotshells for ducks but that is the only use that I have ever heard for it. It is apparently brittle as you mentioned.

[RogerDat]

My reading on using it for Pb free bullets lines up with what people are saying here. Brittle unless enough tin is added to make it more ductile. At 47% tin I think that is covered but in Michigan we don't have lead free bullet areas, just non-toxic for water fowl. Don't think I have any good way to cast it in water fowl sizes. Maybe #4 buckshot would be a possibility. I think the waterfowl shot sizes are large for a dripper, small for a round ball mold.

I have about 25 lbs. of it so as a source of 2% tin for WW alloy the couple percent of Bismuth getting added along with the tin sounds like it won't really hurt anything. Would cover the tin for a whole lot of WW's. Might have to test and make sure I don't end up with bullets that fracture along the bismuth grain lines despite being around 94% lead.

I was only half joking on the slingshot ammo. Non-toxic so the one grandkid with a slingshot could use it safely. Well as safely as a boy with a slingshot is in general. Maybe a Lee dual cavity RB mold and off he goes. Give him an excuse to do some casting.

[country gent]

Windows light bulbs mailboxes and many other items wont benefit from the leadfree sling shot ammo LOL

[JMax]

Lead bismuth forms an alloy the melts at about 98 degree C and has caused reliability problems in an old Canadian telecom co equipment due to premature solder joint failures. Use it with tin only but absolutely no lead in the mix or you will experience unusual results.

[RogerDat]

Lead bismuth forms an alloy the melts at about 98 degree C and has caused reliability problems in an old Canadian telecom co equipment due to premature solder joint failures. Use it with tin only but absolutely no lead in the mix or you will experience unusual results.What about 2% bismuth 2% tin with 3% antimony and 93% lead? Will the small amount of bismuth impact the melting temperature in the same way as the Canadian telecom found?

Thinking just using it to add the 2% tin to the alloy I'm casting.

[RogerDat]

Windows light bulbs mailboxes and many other items wont benefit from the leadfree sling shot ammo LOL You might have a point there. However he is a grandchild. You know, hurry up and finish that twinkie and can of Jolt soda your mom will be here in a few minutes. Windows, mailboxes and other items will be in his parents neighborhood and I prefer to think of that as providing a teachable moment if anything goes amiss.

[JMax]

What about 2% bismuth 2% tin with 3% antimony and 93% lead? Will the small amount of bismuth impact the melting temperature in the same way as the Canadian telecom found?

Thinking just using it to add the 2% tin to the alloy I'm casting.
It would be best to do some experiments, there may be enough lead to minimize fractures, PbBi phases will be the last to solidify and will probably not occur while the bullet is still in the mold. There may be mealie internal consistency if allowed to slow cool. Perhaps water dropping from the mold would help. I would use the coated bullet smash test right off the bat to determine if these PbBi phases are large enough to cause bullet flight or fragmentation in the barrel issues.

[Gewehr-Guy]

Do you know what the melting temp is ? It might be useful as a chamber casting alloy, if it doesn't shrink or grow too much after cooling. Someone here might know how it compares to an alloy like Cerrosafe.

[Traffer]

Do you know what the melting temp is ? It might be useful as a chamber casting alloy, if it doesn't shrink or grow too much after cooling. Someone here might know how it compares to an alloy like Cerrosafe.

^^^^I thought this same thing^^^^

[dondiego]

#4 buckshot would work for geese. You could use up some of your zinc contaminated pewter and solder for those too.

[RogerDat]

#4 buckshot would work for geese. You could use up some of your zinc contaminated pewter and solder for those too. Oh someone just had to remind me of the zinc contaminated pewter didn't they? Looking forward to sending in a sample to BNE for testing now that it has been sulfur fluxed with garden sulfur. See if the zinc was pulled out. Plan on testing with acid too. See if BNE finds zinc at levels below where acid test will. I'm thinking there is a good bet XRF does find zinc that acid would miss.

That pewter was sort of slated for slingshot ammo. Very expensive tin slingshot ammo. Or possibly a paper weight if I find a mold I like.

This alloy is really close to this one from Rotometals. https://www.rotometals.com/lead-free-fishing-tackle-weight-bismuth-tin-alloy-281/

May make the most sense to just melt it into ingots, get it tested so I know what the alloy is for certain. Then wait for a use to come up. Maybe a California caster will be working on Condor safe bullets, or someone that makes fishing weights will want it for Pb free weights. I have plenty of tin from solder or pewter so don't have to use this. Considering Rotometals wants over $13 a pound for it I'm thinking a bit too high priced for slingshot ammo. Even the zinc contaminated pewter is cheaper.

I might give #4 shot a try if anything. Lee makes a mold for that and I'm guessing with that much tin the stuff would flow well, even into that string of pearls buckshot mold from Lee. Be interesting to see if tumbling the shot reduces the "nib" the way it does in buckshot cast from hardball lead.