Alloy Quizeler!

[Rick]

I agree with Jim, there would most certainly have to be inconsistency with that method. As for the rest of your questions, there is no way to get the alloy any softer than what the base alloy is air cooled. After such annealing there may be some age hardening but probably not a lot.

If I were to try what your suggesting I would line up the heat treated bullets in a pan such as a pie tin, fill with water leaving the noses exposed and place in an oven at about 400 degrees for at least a half hour, Don't quench, allow to cool to room temp. At 212 degree of boiling water there could be minor annealing of the bases but not nearly as much as the exposed noses.
.

 

[fiver]

for the first day or so you'll have the same effect as a newly cast bullet then it will harden to the air cooled alloy's bhn.

 

[Chris]

They will, over time, harden just the same as air cooled bullets of the same alloy. That is what that portion of the bullet has become.

Magnum shot is what, maybe 3% Sb? Add 1% Sn and you have an alloy similar to what many use except it contains far more As and will heat treat harden pretty fast.

The lead alloy spreadsheet says 4-6% Sb depending on shot size and 1.25% As. Chilled shot is 2% Sb.

Using the spreadsheet Paco's mag shot + 5% Sn comes to BHN about 15.

If waterdropped, this might make BHN 20-22 I think. So how soft will those noses become when de-tempered? About 15 BHN as the parent alloy hardness? Or is it possible to reduce BHN below the 15 used in this example?

As a sidenote, this much Sb would make the bullet somewhat brittle. You suppose this much tin restores acceptable ductility?

 

[Chris]

Sorry, I see that Rick answered above that the de-tempered nose can not become softer than the parent alloy. That makes sense. Thanks.

 

[Brad]

That alloy would be, in my mind, brittle.
I would rather use a 2 % Sb alloy and heat treat to what I want.

I can assure you that not many topics in cast bullet shooting is as divisive as "hardness". I went down the "hardcast" route for a bit. Dos OK but used lots of expensive alloys. I now use almost exclusively range scrap or range scrap/monotype mixed 10/1. I get better results and save lots of money too.

I just don't shoot anything where a 22 BHn bullet is really an asset.

 

[KHornet]

I never tried the stand in water and heat the nose bit. I much prefer however the
Bruce B method, but not as detailed as Bruce did it. Just two batches of lead going at
the same time, one for the nose of pure lead, the other with a harder alloy for the bullet
body. Bruce's way leaves on visable line to see, but Brad and I have both had no problem
seeing a line between the soft and the hard shooting wise.
Paul

 

[Chris]

That alloy would be, in my mind, brittle.
I would rather use a 2 % Sb alloy and heat treat to what I want.

I can assure you that not many topics in cast bullet shooting is as divisive as "hardness". I went down the "hardcast" route for a bit. Dos OK but used lots of expensive alloys. I now use almost exclusively range scrap or range scrap/monotype mixed 10/1. I get better results and save lots of money too.

I just don't shoot anything where a 22 BHn bullet is really an asset.

The hardness debate can rage on without me, but hardness/toughness of ternary lead alloys and their application sure is an interesting matter. "The art and science of bullet casting". There are people who have forgotten more about this than I will ever know, so I'm grateful for the opportunity to learn.

At a practical level, at this point in my rifle cast shooting and hunting, I'm satisfied with an alloy of WW+2% with maybe a sniff more lead at BHN's of about 18 or 11 depending on which rifle and load. I may be satisfied now but I'm still exploring and having fun at it.

If there is room for another question: what, if any, are the consequences of a ternary lead alloy containing substantially more Sn than Sb?

 

[Brad]

I have never tried that but have heard of others who did and it wasn't a good thing.
Maybe fiver or Ian will chime in pretty sure they each have been down that road.

We plus a little tin will never be a bad alloy for anything.

Hardness is a tough topic as it isn't as simple as people want to make it. It must be balanced with velocity and pressure too. I shot a deer with a too hard HP in a 350 gr 45-70. Hit the shoulder, blew the nose off, and ended in the neck. Luckily I did end up recovering the deer after someone else finished it off for me. Hard lesson to learn. Had it been a 500 fps slower who knows what might have happened. A solid would have been better yet.