How often to anneal brass

A couple of years ago, I ran into a fellow at the local range who was having extraction problems and asked for advice. I could see nothing wrong with the rifle, but his brass showed signs of high pressure even though the load he was using seemed moderate. Then he told me that after reading about annealing the brass, he did so by placing the cases on a vise and heating then red hot with a torch!!

I told him that was NOT the way to anneal cases. He clearly didn't believe me, but asked one of the RO's who told him the same thing. Then he wanted to know how he could save the cases that were already dead soft. We told him to toss them (not in the range bucket, please) and buy some more, either brass or ammo. He said that he had no intention of wasting the amount of brass he already had and would just continue to load and fire it and that we obviously had brass we wanted to sell him (we didn't). When I asked how much brass he had, it turned out that the box (20 rounds) was all he had or had ever had. I asked if his continued health or even life was worth the cost of a box of ammo. He gave me an easily understood indication that I should engage in some biologically impossible activity and stalked away.

I never saw the guy again, so I don't know how long that box of brass lasted until it finally let go. And I really don't care.

Jim
 
Owning a Rockwell tester, and being curious (and bored), I've tested brand new cases from the three biggest makers.
I've also seen how two of the largest makers produce brass.

At the factory, a 'Cup' of brass is dropped into a pin press/die, and extreme pressure is applied until the brass becomes 'Plastic' and forms to the die.
Brass is then dropped into a liquid salt bath and annealed.
The neck gets further annealing as it goes through further forming to produce the shoulder.

The case body is about 'Half Soft', while the neck is 'Dead Soft', but not over heated enough to seperate the alloys from the brass.

The biggest problem I see with home annealing (and I made the same mistakes until I spoke with factory engineers & metallurgists that deal with non-ferrous metals),
Its both controlling the heat applied, AND making sure the case is heated throughout, all the way through...

Making the neck/shoulder 'Dead Soft' (industry term) keeps the brass from torsion cracking during use (firing expansion).

Allowing *Some* of the heat to creep down into the case walls doesn't hurt anything to prevent cracks, but dead soft side walls WILL migrate forward during resizing, causing the case/head seperation we all love...

I'm NOT trying to tell you what to do,
I'm trying to get some information out there, let you make up your own minds...

Manufacturers have switched from gas/flame annealing to electrical induction annealing.
Electrical induction gives the manufacturers EVEN HEATING throughout the case materials, while keeping the annealing up high in the case, concentrated at the shoulder/neck.

The factory engineers also told me to get rid of the MAPP gas and plumbers torch, use SMALL torches (plural) and spin the case.
This gives you more even, consistant heating in the shoulder/neck.

They also told me to throw the temp sensitive paint away and get a pyrometer.
Often the paint is off by 500 degrees or more.

Now, I never found a way to effectively use an infrared (no contact) pyrometer while applying heat with torches,
But it works great with electrical annealing.
A contact type pyrometer isn't nearly as inexpensive as an infrared 'Pistol' type pyrometer... Contact probe type pyrometers run about $300, while infrared 'Pistols' run about $20 to $60.

Electrical heating works MUCH better on metals that have electrical resistance,
Brass doesn't have a lot of electrical resistance, so it takes MUCH more power to electrically anneal brass than heat steel,
Even though electrically annealing heats the brass VERY evenly & throughly, it takes a lot of power compaired to steel.

Gas heating cooks the outside of the brass, and often cooks alloy metals/minerals out of the brass.
Small torch heads (more than one) will heat more evenly and allow heat to creep through the brass without as much of a chance of overheating the outside of the brass...

Just some thoughts on the subject.
 
Allowing *Some* of the heat to creep down into the case walls doesn't hurt anything to prevent cracks, but dead soft side walls WILL migrate forward during resizing, causing the case/head seperation we all love...
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Had someone in a lab and or an engineer described the chain of events above as fact I would have said; "FANTASTIC" and I would have gotten away it unless the lab person or the engineer attended the same finishing school I attended.

F. Guffey
 
Owning a Rockwell tester, and being curious (and bored), I've tested brand new cases from the three biggest makers.
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You are the only other person I know of that has done this. I am curious, how you tested them, not as easy as just chunking a part in there, pretty tricky actually.
 
Would some one elaborate on using a pyrometer while using torches. Including what kind of meter and where it would be pointed? Thank you
 
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Would some one elaborate on using a pyrometer while using torches.
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I have a pyrometer with 8 selections meaning I can test the temperature in 8 different places by rotating the selector. I have pyrometers that use one pickup. I have the point and click type that are sold by Harbor Freight. The most unreliable is the one from Harbor Freight; it is 8 degree off when checking boiling water.

But if someone decided to rig up a tester I would suggest they take the temperature at the shoulder or if they intended to form cases I would suggest they anneal the case down to the point they anticipated the new shoulder would be located.

And as always I suggest if someone is going to start annealing they try to identify rules for annealing, there are rules and they are simple.

F. Guffey
 
Small detail; when using a pyrometer while using torches. If the pyrometer is in the flame the temperature reading will indicate the temperature of the flame.

F. Guffey
 
IR thermometers can be quite inaccurate measuring reflective surfaces.

If you would like to test one, melt some lead, and skim the dross so it's a mirror and take a reading.
 
I've only annealed brass cases in the past when I was wanting to fire-form them to change them in some major way, such as to an "improved" (like K-Hornet)configuration or to a different caliber(like 6.5JDJ). Doing it then will reduce split necks, et.
Otherwise, I don't bother. Depending on how hot you load them, you're likely to get case head separation before split necks IME.
 
IR thermometers can be quite inaccurate measuring reflective surfaces.

If you would like to test one, melt some lead, and skim the dross so it's a mirror and take a reading.
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That does not work for all the same reasons nothing works when reloading. There are variations and differences between specifications and then there are tolerances.

F. Guffey
 
I have to anneal my Weatherby brrass every third shot. As it keeps getting more expensive every other shot might be better.
I set in a large aluminum pan, for the quantity of water that comes up to about eighth inch below shoulder. Watch for brass in mapp gas heat to come up to light cherry and tip the case over into the water.
Need a more up to date technique for right temp etc. I have collapsed a few shoulder when seating the bullet. The shoulder needs a little annealing too though, as I've had a few crack right down to where the shoulder starts.
You can feel the brass when it hardens with your finger and fingernail.
Military ammo shows clearly the brass has been in flame for a period of time being annealed. heavier brass, and trip down line, of burners and quinched.
Many military 5.56 after firing is still soft. The dents and so forth in the neck are easily removed when reloading.
I've only encountered several out of a few hundred that cracked.
Clearly some of the reloads we buy and some of the "once fired brass" was just once fired out of their gun after being reloaded perhaps several times.
I've had several rounds of these rounds out of a few hundred break when fired or upon ejection.
I'm not aware of but a production type piece, of equipment ,for annealing all used 5.56 brass would b a good idea.
 
I've only annealed brass cases in the past when I was wanting to fire-form them to change them in some major way, such as to an "improved" (like K-Hornet)configuration or to a different caliber(like 6.5JDJ). Doing it then will reduce split necks, et.
Otherwise, I don't bother. Depending on how hot you load them, you're likely to get case head separation before split necks IME.
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Case head separation is cured by minimum shoulder setback.

I know I am a skipping record, I think most annealers fool themselves. Good news is too soft ok as long as it does not go down the case. No enough only someplace in between with split neck eventually.
 
At 14.7 psi (1 atm), if you raise the pressure you also raise the boiling point.
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1 millibar = 0.0145037738 psi
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And if I was making a wild guess and going the other way I would say the boiling point drops about 3° for every pound of pressure reduction. And then there is certified, warranted guaranteed or your money back lead. I have some; problem, most of the companies that stamped the bars are no longer in business.

F. Guffey
 
but if I wanted to raise the boiling point of water in my radiator 45 ° I would use a 15 PSI radiator cap. And then there is that other factor; adding anti freeze raises the boiling point of water.

F. Guffey
 
You can also boil water at room temperature in a vacuum chamber, about 29 inches of mercury for about 70 deg F.

But it will not help you anneal brass. :)
 
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