Hardness increase using cold water drop

[arthury]

I am reading from Veral Smith's book about casting and he seem to indicate that by dropping into cold water, you will increase the hardness by, at least, twice; sometimes, even more.

In my first session, I had some dropped into dry towel and others dropped into a bucket of cold water with floating sponge and measured their hardness using Lee's Hardness Die method.

I got:

dry towel: 8 BHN
cold water shock: 10.8 BHN


That's no where even close to twice. What are your experience?

[Huskerguy]

Some questions on your experiment.

1. How many bullets did you check with each? It would seem that at least 10 of each would give a decent average.

2. Did you check BHN with nothing? So you could have another control group.

3. I have heard some people say dropping them on a wet towel works as well so there is another group.

1. Dropped into a dry towel - no quenching of any kind
2. Dropped onto a saturated wet towel.
3. Dropped into water
4. Exact same number of bullets in each group to get an average.


I have seen people state that BHN changes over time as well. I have no clue, I do not have a gauge. I will be interested to see more of this experiment.

[462]

Measure the water-quenched boolits once a week for a month, they'll get harder.

[RobS]

If you are going to water quench in a pail of water it will need to have anitmony in the alloy. Wheel Weight Alloy is a good example and as a trace of arsinic in it as well with helps quicken the aging process.

Tell us what alloy you are quenching 1st and then tell us how long it was since you water quenched when you did your BHN testing. It takes time for your bullets to age harden.

[arthury]

Measure the water-quenched boolits once a week for a month, they'll get harder.

You're right. I just re-read the section in Veral Smith's book and he did say that it will peak in its hardness in about 12 hours after quenching. Thanks!

[arthury]

If you are going to water quench in a pail of water it will need to have anitmony in the alloy. Wheel Weight Alloy is a good example and as a trace of arsinic in it as well with helps quicken the aging process.

Tell us what alloy you are quenching 1st and then tell us how long it was since you water quenched when you did your BHN testing. It takes time for your bullets to age harden.

Currently, the ingots I got were smelted from expended bullets. So, I do not know the exact composition of the alloy. But, based on the Hardness Tester, I am getting around 8 BHN (about 45 min after casting) so, I am thinking it's a pretty softer alloy.

I will get getting harder mixes soon.

[geargnasher]

You're right. I just re-read the section in Veral Smith's book and he did say that it will peak in its hardness in about 12 hours after quenching. Thanks!

It might, and then again it might peak in three years, no kidding. A month or two will usually give you the best indication of what you're going to get. It depends on the concentration and combination of certain trace elements in your particular batch of alloy.

Gear

[MtGun44]

Gotta wait for the hardness, and it also is dependent on the particular alloy. 21+ BHN
readily attainable. I find no benefit for pistol boolits, so don't bother.

Bill

[arthury]

It might, and then again it might peak in three years, no kidding.

Ahhhh ... no one told that casting bullets is like making wine? You need to let it age for years? :-D


A month or two will usually give you the best indication of what you're going to get. It depends on the concentration and combination of certain trace elements in your particular batch of alloy.
Gear

I'll let it sit and re-test.
Thanks!

[RobS]

Gotta wait for the hardness, and it also is dependent on the particular alloy. 21+ BHN
readily attainable. I find no benefit for pistol boolits, so don't bother.

Bill

Man, Bill...........the hard guys and then the soft guys. You all just can't help but state your likes and dislikes. :-D

[arthury]

Gotta wait for the hardness, and it also is dependent on the particular alloy. 21+ BHN
readily attainable. I find no benefit for pistol boolits, so don't bother.

Bill

I'm casting bullets for 500SW magnum. Would you think hardness will not really matter?

[RobS]

Currently, the ingots I got were smelted from expended bullets. So, I do not know the exact composition of the alloy. But, based on the Hardness Tester, I am getting around 8 BHN (about 45 min after casting) so, I am thinking it's a pretty softer alloy.

I will get getting harder mixes soon.

Actually 8 BHN 45 minutes after casting from what sounds like range scrap isn't too soft. If these air cooled bullets or ingots harden in a weeks time to 11 to 13 BHN then the alloy likely has antimony in it. You'll know if you have antimony in your alloy by water quenching and testing your BHN. If the test samples are harder than your aircooled in the same given time.........say 24 hours later there's antimony. As to what % and if there are other trace elements in the alloy that will come out in the wash.....or time as it ages and you test for it.

[RobS]

I'm casting bullets for 500SW magnum. Would you think hardness will not really matter?

Hardness very well could matter especially if you stand on it and are shooting a PB boolit design. I shoot a 454 Casull and having a harder bullet is simply more accurate for my revolver. There is less skidding and hand in hand less leading. Other loads I shoot in revolvers are just fine with an air cooled WW boolit. Find out what is best for your 500 and go from there is what I'm saying.

[lead chucker]

I made some 50/50 WW to pure lead plus 2% tin the the pure part air cooled it measured a brinell hardness of 7 and it stayed there for a couple weeks it was a little softer than I wanted so I put them aside and a couple weeks later I tested some of them just for the heck of it and they were a brinell of 10 it took at least a month for them to get that hard. It was what I wanted as far as hardness went. It is strange how lead works.

[Bret4207]

Just to be clear, both AC and WQ take time to harden. Figure about 3 weeks for both to achieve something near final Bhn reading. But- if you'll do some reading you'll find Bhn is just a relative number and no more. You can have the same alloy treated 3 different ways give 3 different readings or 3 different alloys with varying characteristics give the same reading! "Harder" means nothing unless you are using the same alloy throughout your growth as a caster. Change the alloy and Bhn means less than nothing in that sense.

[btroj]

I am with Bret on this one. Entirely.

Hardness can be altered so many ways. I can add tin, add antimony, I can add aresenic, I can water drop. All change hardness, all in slightly different ways.

I can take a standard wheel weight, water drop it and get it as hard as Linotype air cooled. The two bullets will behave quite differently if used for hunting.

BHN tells you ONE parameter about your bullet. Hardness. How you got that hardness is far more important than what it is!

Stop thinking aout what the hardness is, start thinking about why it is.