Aging lead

burbank.jung

Active Member
How long do you leave your cast ingots and cast bullets sit so the molecules settle and the bhn stabilizes before you determine its bhn and use them as testloads?
 

waco

Springfield, Oregon
I think it kind of depends on what your alloy is made of. My rifle bullets cast for high speed long range work will set for a month or more before I use them . These are 90/6/4 and water dropped. They end up around 18-20bhn.
Handgun stuff? I just cast and shoot. It all depends on what you are trying to do.
 

burbank.jung

Active Member
I usually don't use my ingots for a few months. I suppose it's safe to do a hardness test after a month so I can group them into batches. Then, I usually cast by combining those batches. I have another question that's off topic so I'll start another thread. The highest percentage of antinomy I've found for commercial bullets is 3%. Is this close?
 

Rick

Moderator
Staff member
Like Ric said, it's all the percentage of Sb related. But ingots? Age them all you want but as soon as you melt them, you're back to ground zero.

I heat treated bullets one time to 30 BHN as an experiment and put them under the bench. Found them again 10 years later, they were 26 BHN. Alloy was CWW+ 2% Sn. Sn also will effect final BHN by reducing the hardness and increasing the rate of age softening, but it takes about 5%+ to do so.
 

Brad

Benevolent Overlord and site owner
Staff member
I don’t age them but I do cast to keep a supply on hand. That means I may be shooting 3 month old to 5 year old bullets.
I really don’t like shooting stuff less than 2-3 weeks old but sometimes one does what one must.

I tend to store bullets, unsized, in bulk. I usually powder coat them and dump them in a bin for storage. I size a few hundred ahead and then load.

Ingots don’t need to age, like a Rick said melting them down eliminates and changes made.
 

BudHyett

Active Member
This is my experience. 94/4/2/ alloy cast bullets, water dropped into a bucket with dry ice in it will slow age soften from Brinell 28/30 to Brinell 22/24 over a period of five years. Not exactly a scientific test, but observed. My uncle gave me some bullets that I did not shoot for five years and checked out of curiosity. These bullets at 22/24 hardness shot as well as freshly cast bullets.

Secondly, Ric is right. Casting starts the cycle all over again. Changes in the alloy crystalline structure do occur. The Lyman Cast Bullet Manual has an article on alloy that mentions the growth of dendrite trees in the alloy as it ages. This changes the shape of the crystalline structure, but what effect does this have on the shootability of the alloy?

(Sometimes I think we are in the reloading room chasing attributes when we should be at the range practicing.)
 
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Intel6

Active Member
I don’t age them but I do cast to keep a supply on hand. That means I may be shooting 3 month old to 5 year old bullets.
I really don’t like shooting stuff less than 2-3 weeks old but sometimes one does what one must.

I tend to store bullets, unsized, in bulk. I usually powder coat them and dump them in a bin for storage. I size a few hundred ahead and then load.

Ingots don’t need to age, like a Rick said melting them down eliminates and changes made.

Same as Brad on this one. I try and keep a backlog on bullets so they are coated/sized and sitting for some time before I end up using them. When I know I am running out of a certain bullet I make sure they are a priority for making more.

Of course, there are times when you can't do that like when you get a new mould. In that case I try and be patient after coating and casting and wait at least a week or two before loading.
 

burbank.jung

Active Member
Like Ric said, it's all the percentage of Sb related. But ingots? Age them all you want but as soon as you melt them, you're back to ground zero.

I heat treated bullets one time to 30 BHN as an experiment and put them under the bench. Found them again 10 years later, they were 26 BHN. Alloy was CWW+ 2% Sn. Sn also will effect final BHN by reducing the hardness and increasing the rate of age softening, but it takes about 5%+ to do so.
I agree. But wouldn't it be logical to say that if I cast the ingots into bullets and PC'd them, then let them age, the final BHN would stablize to be the same or close to the ingot BHN? Atleast I have a better working number to work with than a random ingot. How much variation in BHN have you found in your cast bullets before your accuracy changes? eg: +/- XX BHN.
 

burbank.jung

Active Member
Same as Brad on this one. I try and keep a backlog on bullets so they are coated/sized and sitting for some time before I end up using them. When I know I am running out of a certain bullet I make sure they are a priority for making more.

Of course, there are times when you can't do that like when you get a new mould. In that case I try and be patient after coating and casting and wait at least a week or two before loading.
Have you experienced resizing issues with a freshly PC'd bullet vs an aged bullet?
 

Rick

Moderator
Staff member
I agree. But wouldn't it be logical to say that if I cast the ingots into bullets and PC'd them, then let them age, the final BHN would stablize to be the same or close to the ingot BHN? Atleast I have a better working number to work with than a random ingot. How much variation in BHN have you found in your cast bullets before your accuracy changes? eg: +/- XX BHN.

Nope, doesn't work that way. The percentage of Sb AND how fast they cool determines the final BHN. An ingot being of far greater mass will cool slower even if you water quench than will a much smaller bullet. That is the reason you cannot accurately BHN test ingots.

After years testing accuracy loads for long range revolver It's my experience that variation in BHN within the same group is far more important for accuracy than is shooting a specific BHN.

You didn't say what you're shooting or trying to do but I can assure you that for the vast amount of cast bullet shooting the BHN is far down the list of what's important. Don't get yourself wrapped around the axle trying for a specific BHN. For one thing you can have several bullets made up of different alloys and they all could test the same BHN. Far more important how they perform on target than they are a specific BHN.
 

Brad

Benevolent Overlord and site owner
Staff member
Have you experienced resizing issues with a freshly PC'd bullet vs an aged bullet?
Not at all. Might be because any bullet I know will be sized down much at all gets sized before PC and again after. It adds work but gives me better results than sizing down a bunch after coating.
If I found PC bullet took much effort to size I would add a tiny bit of wax to ever 10th to 15th bullet with my fingers.