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View Full Version : Bismuth alloy info: Lead-free projectile alloys



Littleton Shot Maker
02-16-2018, 01:45 AM
No it's not LEAD, But I would like to begin a spot some where on the forum where I, and other shooters can post up all the useful info possible concerning BI. and Tin Alloys??

Not sure it is just shotgun specific so would it makes sense to have a section HERE? in the 'alloys' sub-forum??

Seen allot of questions lately and taken more than just a few calls over the past 6 months on just this topic.

PURE Bi. does not work for our ( shooter's) purposes AT ALL.

SHOT: needs %5 tin alloy with Bismuth
Buck and slug: needs %30 tin alloyed into the mix in order to hold together in the barrel upon ignition and not frag upon impact.

More tin drives the cost up and drives the melt point down, that could be a real bad thing if that melt point gets too low.

Just think : the barrel will be HOT while the FIRE is pushing 'slug' out...does that come out as a chunk or a big squirt, a mix of the two??
I don't want to find out the hard way>>> Neither should you.

MODS please move if you feel the need, but we do need a spot for this info and make it a resource for every one interested in a NON-Tox. projectile alternative . Thanks

Mxrick55555
02-16-2018, 02:18 AM
I think I have accidentally added some bismuth to my lead mix if I remember right the boolets seemed to shrink a lot once cooled and the spure didn’t cut very cleanly almost like chunked off. It was a while ago that this happened when I first got into casting my own I got a score on 1200lbs of scrap lead and there was about a half 5 gal bucket of these ingots that sounded different than the other ingots when dropped on a concrete floor. More of a ting than a thud I though it must have more tin in it until I tried to cast with it now those ingots are in a corner in the shop figure if I ever run out of lead I will try to make them work somehow lol.

Littleton Shot Maker
02-16-2018, 11:29 AM
Pure Bismuth expands as it cools…it does NOT expand evenly . Lead shrinks as it cools , it cools the same on all side - and is predictable-
Bi expands at an uneven amount. it looks like rough and grows slighlty ( like water-and ice) so the %5 tin crontrols that to some degree and also helps will the flow out of the drippers and for sure the %30 tin alloy will help when you are trying to get in the molds-

Casting is a PITA- if opening the molds too late you take out a chunk from the sprue side and too early and it leaves a smears real bad

All the same issues as lead but X50- temps are super critical here-

Too hot an alloy and you fail- too cool and you won't get it to pour at all…….

Let me review my notes and find out what we had the Master Caster set at when we did the last run of .36 cal. ball we did…and I will post those here.

I was told "too much TIN will shrink" a bullet bad and it does have that PEEEEEN sound .

Never tired to use more than 10%tin - 90 lead max. in rifle rounds and 7-6% in pistol bullets…

the Bi was a PEEN sound compared to lead or tin and the lead was just THUMP sound followed by an "ouch!" when it hit your toes

JonB_in_Glencoe
02-22-2018, 04:12 PM
I edited the title and made this a sticky.

TCLouis
09-09-2020, 11:04 PM
I have some "tin" I bought years ago that has 2% bismuth, when I use it to bring lead up to 2% tin is the bismuth even going to be an issue?

sw282
08-14-2022, 12:40 AM
l have a funny story of ''BI''. 40+YRS ago l got some stick ingots marked BI. They were heavy, soft, and shiny. l stuck some in my pot and the poured into my Lee swc 44 mold. Out came shiny 44 boolits. l sized, lubed and loaded up some empty 44Mag cases with 9gr of Unique, setting them aside. A few weeks later a friend and l went to my pond after work for some shooting. l had my Smith 44 magnum revolver and George had his 44 Lever gun. l think it was a Browning. We set up a target at maybe 40yds. l fired a cylinder full. The target looked like a shotgun pattern instead of a group. George's attempt was even WORSE. His bullet holes seemed to have splatter around them. What was going on?? The blame quickly zoomed on MY ammo:sad: We shot across the pond lengthwise with his rifle noticing a spray pattern on the water. My Smith was not as bad. We finally figured out the boolits were melting inside the 24'' barrel of George's 44 rifle. Lesson learned: Pure Bismuth makes sorry cast boolits:oops:

GregLaROCHE
08-14-2022, 05:37 AM
I’ve been following the forced move for many to non lead projectiles. Luckily, I don’t yet have the problem. If or when I need to change my metal, I plan on trying zinc.

popper
08-15-2022, 06:16 PM
Roto has a bismuth alloy, has been cast and shot OK (223). Not cheap so use as last resort.

Krh1326
04-21-2023, 11:24 AM
I am in this boat now, as my Commie state is on the verge of a lead ban. A lot of the common and popular white tail cartridges just don’t seem to have many manufacturers producing alternatives.
Meaning our level guns and muzzle loaders. I’m particularly concerned with .35 Rem and 30-30.

I’ve replicated two lbs of Roto’s bismuth alloy. I’m seeing wierd stuff right away. My muffin tin ingots grew tumors. And i don’t see being able to pc, with its low melt point.

I found a few articles on Artful Bullet… hey Popper… are you the same Popper there?

Bigslug
04-29-2023, 12:11 PM
My dad fiddled around with the Rotometals alloy, increasing the tin percentage to varying degrees. I think he even got as far as ordering a custom mold or two for it. What we found:

* It wasn't hard to get the stuff to group acceptably.

* Our impact testing was in MK1, Mod 0 gallon milk jugs full of water. Below a certain tin percentage, the bullets will shatter. More tin will reduce the weight. I don't recall if we got to where we knew what the happy medium was.

* I don't think there's any chance of getting the stuff to expand unless you want to lean a little more toward a higher tin percentage and can get a decent cast in a hollow point mold. Anything without a cavity in the nose is unlikely to deform. It makes a good argument for a larger starting bore diameter.

*I know there are some areas (maybe foreign countries) that insist on an expanding bullet. This may somewhat paint us into corner for non-lead options.

* Basically, what I THINK we're dealing with is a material that will give us a lighter bullet that we can move out of the barrel faster, but that we'll need a large meplat for tissue damage effects because it won't mushroom. These characteristics will give us an acceptably flat trajectory, but only over shorter "brush gun" distances.

* The conclusion Pop and I came to is that if you NEED to shoot a lead-free cast bullet because you're using a rifle with a weird bore diameter, it has a place. If, on the other hand, you are running a "meat and potatoes" caliber like .243, 6.5, .270, 7mm, .308, .338; you're better off doing your actual hunting with a monolithic copper bullet like the Barnes TSX line which is known to expand in meat and can be driven hard while using your cast lead to practice with in the off-season. (That said, we're hunting in So. CA and our shots have been mostly at ranges where a .30-30 is starting to stretch. If we were back east where most deer can be killed with a stone axe to the head, I'd have no qualms about using this material for the "straight wall" zones)

That grates on me from the perspective of being dependent on a store bought bullet, but in a cost/benefit analysis, when you add up ALL the stuff we spend money on for hunting season, a $1.00 solid copper bullet that flies flat, is accurate, is highly effective, and (after initial load development) only gets fired to periodically confirm zero and kill game is an absorbable cost. At the point of an actual Zombie Apocalypse, the eco-weenies forcing this on us will be the first to have brains eaten by the undead; the game wardens will be out of a job; and we'll be back to lead anyway.:mrgreen:

That was where OUR R&D petered out, but I'm still very interested in how others fare with it.