Bismuth and lead free casting?

[Barry54]

https://www.rotometals.com/lead-free...bismuth-based/

Rotometals has this alloy available for casters to use where there are lead bans in effect.

Have any of you cast with this alloy or other lead free alternatives? How are your results?

Please keep this thread on the topic of lead-free alloy casting!

[JonB_in_Glencoe]

Did you see the link rotometals has in description?
That is the only testing documentation of casting, target shooting, and game animal shooting, that I know of.

[Barry54]

I consider this forum to be the premier source of information on casting. I’ll be patient and see if anyone here has tried it or others.

The alloy from Rotometals is expensive in my opinion but it is less dense than lead. So that 1 pound of alloy would make an equivalent 9000 grains of boolits.

Zinc is also lead free...

[JonB_in_Glencoe]

so you didn't read it?

[Barry54]

so you didn't read it?

No I have not studied all eight pages of it yet. Was there something in particular you wanted me to see?

I am not interested in the Rotometals alloy exclusively. Lead is one element on this entire planet and I am interested in casting with everything else that may work. I used the Rotometals alloy as an example to get the thread started.

[JonB_in_Glencoe]

OK, understood.
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I was just offering my 2¢, since your post started off with the rotometals link.
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The author of that testing thread is a trusted friend of mine and I followed his testing day by day, at the time. Since then, being I live in a State where lead hunting ammo ban looms (legislators have been talking about it for 4 or 5 years). So I follow this topic closely when I see a discussion.
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As to the Testing thread, there isn't one thing or one post to steer you too. The entire thread is a thorough study of what to expect when using that alloy and some pitfalls to avoid. Also there is some hints, tips, and tricks of what type of gun/mold combo works best with that alloy, and what wouldn't work well, and what type of loads to work up. There is also another thread more geared to the science of casting with that particular alloy. Yes, it would seem like a long read, but since both are in discussion format, you will be scrolling quickly through the conversation/chatter posts.

[Barry54]

I promise I’ll study it after dark.

If there’s no profanity or anything else to cause an infraction here, please add the link to this thread.

My rough math for that alloy vs copper 150 grain monolithic 30 caliber bullets puts it at half the cost. Obviously not counting one’s time spent casting.

[JonB_in_Glencoe]

Casting with Rotometals Lead Free alloy
https://www.artfulbullet.com/index.p...ee-alloy.5627/

Lead-free bullet casting alloy
https://www.artfulbullet.com/index.p...ng-alloy.5585/

[Delkal]

It seems like there is a problem with brittleness and maybe even the course crystal structure. This is what you get when you let pure bismuth crystalize.

[Sandspider500]

Here's a chunk of rotometals lead free bullet alloy.




And here's a chunk of pure bismuth.

You can see that the added tin breaks up the large structures into smaller chains.

[Sandspider500]

I cast some lbt 220 fnb with the alloy.

These were cast from a stone cold mold.

Here's the sprue, If the mold gets hot, it takes a long while before you can drop em, as the tin will be trying to leech out.



Here's some tin trying to get out. Weird.


13 good whacks with a hammer on top of a lead ingot and it formed a crack.


15th hit and it gave up the ghost.


It did mushroom quite a bit before breaking.


Came out to 189gr as opposed to 220. Hmm, I need to clean up that powder

[Sandspider500]

I also cast a few hollow points with a mp 454-640.


You can see some of the sprues took a chunk with them. I guess I let it cool a little too much.



I powder coated and baked em at around 250 for an hour. Is that good enough, I dunno. The 2 different hollow points came out 220gr and 223gr.

I'll load them tomorrow, hopefully they won't keep growing, I already sized them, they're very hard, I used some lee case lube to size them. I'll see if they survive the feed ramp in a Glock 21, I think they will. I had read on here someone else tried this alloy in a 357 mag and got horrible accuracy. I'll try at 20yds,

[Barry54]

Great photos! Great looking boolits too! What temperature was your melting pot running?

Do you shoot at a range where you can test the hollow points on water jugs?

[Delkal]

Nice boolits but I don't think bismuth is going to work with a hollow point. It is too brittle and while the hollow point area is guaranteed to shatter once a break starts the rest of the bullet might shatter too.

[Barry54]

It’s an “expanding design” bullet, and meets the letter of the law in some locations.

[Delkal]

It’s an “expanding design” bullet, and meets the letter of the law in some locations.

It will definitely "expand".

[YodaMcFly]

It will definitely "expand".

Have you read the linked threads that talk about actual, real-world performance (as well as lots of interesting metallurgical theory)?

[Sandspider500]

I did a non ballistic test with a hammer and lead ingot, that's as much as I can do. I'm not as lucky as Ian and wouldn't have a chance at a buck on the range I go to. I also have nowhere near me to fire into any kind of test media. Everyone will just have to trust what others have done.

Along with the thread from the other forum. Here's a test done with a shotgun slug.



At 1450fps the slug comes apart, in just about everything it was shot at. Would it still be effective? Absolutely. Maybe if the velocity was reduced, it wouldn't come apart, I don't know, and at what velocity would that be?

My non scientific hammer tests. The bismuth would take some hits from a hammer without breaking, and did expand. Everytime in the very small sample, each expanded from .452 to around .470 before it broke. What does it mean? I dunno probably nothing.




The 220 fnb started out at .61 long and ended up cracking at .505 and expanded to around .470.



Here's the two hollow points after being hit with a hammer, it took around 7 strikes to break them.


Cup point.

It lost some nose before the slug cracked in two, they all seem to crack in 2.

Here's the penta.


And after 3 hits.

And 5


You can see a crack forming on the nose.
]

[Sandspider500]

Here's 7 and 8 hits



I think I wouldn't use the hollow points, but just a flat point. But the cup points would have the look of being designed to expand, even though a flat point would expand just as much before it cracks in two.

If someone could test a large caliber flat point at lower velocities, through water or meat, the bismuth may hold together. On another test I've seen, it seemed the tester was trying to squeeze every bit of velocity out of it and was puzzled why he couldn't find any remnants and sometimes 2 entry holes in his water jugs. Maybe not the best idea to try and shoot these with maximum powder loads trying to break speed records. A big heavy slug doesn't need a lot of speed anyhow.

[Delkal]

Have you read the linked threads that talk about actual, real-world performance (as well as lots of interesting metallurgical theory)?

Yes and I saw no pics of anything that resembled a proper mushroom. All of the pics I saw were either no expansion or broken bullets.

As for metallurgical theory bismuth is extremely fragile and has an unbelievably large crystalline structure so it would not be my first choice for a bullet alloy. While people are trying to reduce these liabilities by alloying tin and other metals they have a long way to go before it can be used on game.

Nothing wrong with experimenting though. But I think experimenting with tin / pewter alloys would be a better place to start. Maybe even zinc.