Bismuth Conicals?

[Ryan Schmitz]

Here's a head scratcher for ya!!! (Maybe not). I was just looking at the web page for the Rotometal folks and saw Bismuth ingots...does anyone here have exp. with casting Bismuth or other lead free alloys into conical type bullets??? Are there any such lead free conicals for sale?? Thanks again

 

[BrownBear]

I'm not a metalurgist, but my first concernin a conical is whether or not bismuth would obturate like lead.

 

[jtmattison]

I looked up bismuth and lead at http://www.mineralszone.com . Lead is 1.5 hardness, bismuth is 2.0 to 2.5 hardness. I don't know what scale they are using but you can see bismuth is about twice as hard as lead. Bismuth also has a lower melting point than lead. I believe wheel weights are also about twice as hard as pure lead. I don't think bismuth would make good conicals. Too hard IMO.

HD

 

[flinthead]

I have an ingot of bismuth I was using for chamber casting on centerfires. It seems quite a bit harder than lead and melts in boiling water!

I don't think it would make a good bullet, plus it is very expensive if I recall.

 

[bingo1952]

Pure Bismuth is also extremely brittle. That was the problem encountered with the early Bismuth waterfowl loads. Upon firing the bottom three or four layers of shot in a load would fracture into smaller fragments. This was solved by the addition of 15% Tin IIRC. This is in addition to the other problems already mentioned.

 

[Zonie]

Most of the Bismuth alloys that melt at very low temperatures have a fairly high lead content.

Cerrobend is 26.7 percent lead.
Cerrolow varies between 17 and 26 percent lead.
Cerrosafe is 37.7 percent lead.
Woods Metal is 25 percent lead.


Cerrocast is lead free being a mix of 40 % bismuth and 60 % tin.
Cerrotru is also lead free being 58% bismuth and 42 % tin.

Either of the last two could be legally used in the California Lead Free zones however I can visualize a situation where the Game & Fish officers would charge you with using lead in your gun.
As these alloys are quite soft and look like lead it is doubtful in my mind that they would believe you when you claimed that the balls were lead free.

The only way out of that box would be to demand that the G&F person take the ball from the gun and save it as evidence. Then hire a lawyer to demand that the ball be analyzed for its lead content and hope the case would be dismissed.

After paying the lawyer his fees, getting out of that charge would probably end up costing a mere $500+.

 

[Joel/Calgary]

The original USF&W approval for bismuth shot was for a 3% tin alloy, and the later increase was only to 5%. FWIW, the toxicity and shot-identification papers I found online suggest that the early Bismuth Cartridge shot was often only 2% Sn or slightly less, which coincidentally is the alloy some of the patents said was the optimum for making shot - probably a temperature/surface-tension function. Ely shot was even worse, with more arsenic than tin in some samples - that would really be brittle. IIRC, folks making bismuth shot with Littleton or similar shotmaker are usually using 5% alloys.

The 5% alloy comes out at somewhere in the range of BHN 18-21 (can't find my reference right now), similar to wheel-weights or a bit harder, and is still more brittle than ductile. This alloy ought to make an OK equivalent of a hard-alloy lead RB, but I doubt it would work well in any conventional conical design without more tin, but that would reduce the density some more.

Joel

 

[CZMark]

Either of the last two could be legally used in the California Lead Free zones however I can visualize a situation where the Game & Fish officers would charge you with using lead in your gun.
As these alloys are quite soft and look like lead it is doubtful in my mind that they would believe you when you claimed that the balls were lead free.

The only way out of that box would be to demand that the G&F person take the ball from the gun and save it as evidence. Then hire a lawyer to demand that the ball be analyzed for its lead content and hope the case would be dismissed.

After paying the lawyer his fees, getting out of that charge would probably end up costing a mere $500+.

When waterfowling in Wisconsin, if a warden suspects you are using lead (usually reloads containing non-ferrous shot) he will confiscate one shell and have it tested in a lab. If it turns out to be lead, you are mailed a citation; if not, you are in the clear, albeit one shell lighter.

 

[CZMark]

When bismuth shot was widely available, I did quite a bit of testing with it. The alloy seemed poor, or possibly there was an incomplete mix of the metals, as some pellets would be fairly malleable, while others were VERY brittle. My tests were always inconsistent, and I believe this was due the inconsistency of the metal.

I would have serious concerns about a bismuth bullet shattering when hitting bone.

 

[Dphar]

Here's a head scratcher for ya!!! (Maybe not). I was just looking at the web page for the Rotometal folks and saw Bismuth ingots...does anyone here have exp. with casting Bismuth or other lead free alloys into conical type bullets??? Are there any such lead free conicals for sale?? Thanks again

You have to understand how conicals work in the typical ML.
They must expand to fill the bore under powder pressure, hard/brittle alloys won't work. Period.
But it is possible to shoot hard alloys when patched RBs are used. This works best if the barrel is cut with very narrow lands and fairly shallow grooves.
With some load development it may be made to work.
The better idea is to band together as shooters and prove the lead ban is the bullcrap it is and get the law changed. Next they will be banning powder because of air pollution.

Dan