?Manipulation of the hardening agents?

[Bigslug]

So I have a source of what appears to be about #7 birdshot - recent production. Out of a desire to figure out exactly what I've got for an alloy, I poured my Lyman ingot mold full of the stuff and set it on the stove to liquefy, stirred it up a bit, and allowed to air-cool. After an hour or two, it was back at room temperature and I put it on the hardness tester and got 8.5 BHN, which seems quite a bit softer than any of the shot categories on our handy forum calculator. I plan to test the same ingots at 1-week intervals to see what's going on by way of age-hardening.

So I've got some hardening questions:

Do air-cooled and water-quenched antimonial alloys get to the same hardness eventually, with water-quenching merely getting the job done faster, or is there a fundamentally different process/structure going on that will differentiate an AC slug from a WQ one until the end of time?

What are the differences between AC and WQ antimonial slugs in terms of how they age?

If you're trying to determine roughly what your alloy is made of through hardness testing, what's your preferred process - testing ingots, testing AC slugs, testing WQ slugs, testing AC or WQ after X-number of days, etc...?

And thanks in advance for NOT responding with "Fit is more important than hardness".

[runfiverun]

part of your problem is shot comes in different grades.
you could have anywhere between 3 and 6% antimony and about .50% arsenic.
my guess is you will be around 13 bhn in a week or so.
if you water dropped it you'll hit about 18-20.

[Bigslug]

That's kinda my hope. If it behaves as you say, I can run it as air-cooled for the slow stuff, and splash it for the .357's and .44's - possibly with some added tin if I choose to hunt with it.

The age-hardening issue is where I'm in need of the most education - do water-quenched slugs change much when left in the wine cellar, or is that mostly an air-cooled thing?

Basically, I'm looking for a straightforward way to determine the properties of this alloy without having to cast a tiny sample quantity, air-cooling some, water-cooling others, and hardness-testing them both after a month.

Anecdotes on how y'all handle shot would be welcome.

[cbrick]

Quenched or oven HT boolits will age soften very slowly after reaching their final BHN, the higher the percentage of tin the faster the softening. The lower the antimony percentage the slower they will age harden.

What determines how hard is the percentage of antimony and the speed they are cooled. I don't test ingots for hardness because the mass of an ingot is far greater than that of a bullet, meaning the bullet will cool much faster.

The only shot I've cast was for 200 gr HP in 45 ACP with 2% Sn, the mushroom was quite impressive.

Rick

[45 2.1]

You should probably go read what Paco Kelley has said about using shot for your lead alloy. Pretty informative if your into speed and results.