Brass Hardening from annealing?

[Koda]

Warning, rabbit hole subject but I think many will be interested.

TLDR: Yellow Brass (aka cartridge brass) contains a high amount of zinc. Unlike pure brass, zinc becomes harder when quenched after heated... therefore, if you quench your brass in the annealing process, it can harden the brass.

<quote>"Since yellow brass has a fairly high zinc content, it's worth taking a look at how this effects the annealing and hardening process. Zinc itself, with minimal impurities, can be quenched and hardened at temperatures between 20-200 degrees Celsius.

In simple terms, brass can be minimally quench hardened. I write this with a big mental asterisk that emphasizes the 'minimal.'

Brass with 30% or greater zinc content has the potential to quench harden in measurable amounts. While it may not be something that reloaders will notice, it can affect the accuracy of reloads.

So, I will say it again, using a torch over water to anneal and then dunking your brass cases will harden them." <unquote>

Now for the rabbit hole: I anneal my brass, and I quench it in water to prevent annealing the case head area via convection. I'm not aware of this causing any issues in my handloads but wonder if this could influence group sizes and velocity spread? Is this worth considering not quenching brass? Can annealing affect the case head area if left unquenched?

My opinion of the article is that while he makes his point, he doesn't provide a solution... hence the "rabbit hole".

Brass Hardening in Reloading

Several months ago, I wrote about annealing cases and some of the benefits and struggles associated with annealing brass.

midsouthshotreport.com

Read More

 

[kmk1012]

I've never annealed my brass. I went through a phase where I picked up tons and tons of it and have enough that I'll only fire it once or twice again in my lifetime. But, I've considered doing it for accuracy before but realized I'm just not patient enough to squeeze that extra .05" off my groups. If my rifles shoot moa or better I'm good. Although it's a very interesting point about the zinc content in cartridge brass, I never considered that factor. Will be watching this thread.

 

[Xmark1]

Years ago, I annealed some 308 and did not quench. Out at the range, I had to use a hammer on the bolt to extract the spent cartridges. The softened case heads enlarged so much during firing that all the cases had to be removed with a hammer. All six that I fired. I ended up throwing away all the remaining reloads from that batch.

I anneal & quench now. And the case necks are visibly softer after annealing. As long as the annealing process is consistent, the neck tension is consistent.
Perhaps zinc content has an effect from a scientific point of view but in my practical reloading experience, I'm not concerned.

 

[dangerranger60]

I'm another that quenches as part of the annealing process. it extends the neck life to near forever in some old oddball cases that I want to keep shooting.
I never thought of it hardening the brass. I do know the annealing leaves the brass less brittle. and helps seal the case in the chamber in lighter loads. DR

 

[Koda]

The article reminds me of the Quinlan-Neville "large sample size" article, where he attempts to refute decades of common reloading practice with some level of scientific discovery yet provides no solution to justify his reasoning.

In my limited reloading experience quenching immediately after annealing I cant say I have ever hardened any brass. I'm up to 7x firings with some of my cases from 223 to 280ai with no signs of fatigue.

Id say if quenching actually hardened brass, people would have noticed by now and it wouldn't be part of anyone's process after all these years.

 

[dangerranger60]

The slight hardening of the brass still has the effect of taking the work hardening out. This is a little like hardening a knife and then going back and tempering. DR

 

[Certaindeaf]

Is military brass quenched after annealing? Probably not.

 

[Xmark1]

The article reminds me of the Quinlan-Neville "large sample size" article, where he attempts to refute decades of common reloading practice with some level of scientific discovery yet provides no solution to justify his reasoning.

In my limited reloading experience quenching immediately after annealing I cant say I have ever hardened any brass. I'm up to 7x firings with some of my cases from 223 to 280ai with no signs of fatigue.

Id say if quenching actually hardened brass, people would have noticed by now and it wouldn't be part of anyone's process after all these years.

It has been my experience that different headstamps represent slightly different alloys.

I have reloaded all the common head stamps over the last twenty years. I have found that each headstamp can be annealed a certain number of times only.
Federal four to six times. Remington easily seven times, etc. The best brass I have found, better than Lapua, is Nosler. I have reloaded my Nosler rifle brass up to twenty-six times with annealing.

This has been my experience. Your results may vary.

 

[Koda]

The best brass I have found, better than Lapua, is Nosler. I have reloaded my Nosler rifle brass up to twenty-six times with annealing.

Just curious if your Nosler brass is old stock, or purchased more recently like maybe in the last 5 years?
Ive had nothing but issues with Nosler brass myself, all newer stuff.

 

[thorborg]

I have been under the impression that worst case scenario is you over heat the brass to a point it reduces the zinc content by burning it out weakening the brass. Zinc melts at under half the temp of copper, so quenching the shell after annealing, while has little effect on the copper, stops any heat rise to help avoid over heating and loosing any zinc.
That's not to say one shouldn't do their best to control the temperature to just what's needed for annealing.

 

[Xmark1]

Just curious if your Nosler brass is old stock, or purchased more recently like maybe in the last 5 years?
Ive had nothing but issues with Nosler brass myself, all newer stuff.

Most of my Nosler was purchased about five or more years ago. I still have unopened boxes of Nosler brass.
I can't speak for new stock. One thing I do know is that the only constant in this world is change.

"The world you were born into no longer exists".

 

[DizzyJ]

I've personally never quenched. If the temperature and location are correct I'm not sure how someone would make it "too soft" further down the case.

 

[arrowshooter]

I'm with DizzyJ . My first shot at annealing came after dealing with once fired LC 5.56 brass splitting necks and shoulders. I used the deep socket in a drill over the flame method and dumped them in the water and it was a PITA drying them out. I quickly learned that the only part of the brass effected by the heat is the part that starts to turn red and water did not offer any benefit to the process other than being able to handle your brass quicker.

 

[osprey]

I have been annealing for the last 4 years or so without quenching with great success. I believe quenching is an unnecessary step that can have unintended consequences. If your annealing process is properly focused at neck shoulder area without excess heat application and brass allowed to cool by natural convection, that is all that is needed.

 

[CLT65]

I've been annealing for years. Sometime I toss the hot brass in water, sometime I don't. I've never had a problem either way. I usually quench when I anneal tumbled brass that's clean and rinsed right out of the wet tumbler, and I have a method for drying it that works really well.

 

[ActBlueDonor]

Unnecessary to quench brass.

 

[dangerranger60]

It has been my experience that different headstamps represent slightly different alloys.

I have reloaded all the common head stamps over the last twenty years. I have found that each headstamp can be annealed a certain number of times only.
Federal four to six times. Remington easily seven times, etc. The best brass I have found, better than Lapua, is Nosler. I have reloaded my Nosler rifle brass up to twenty-six times with annealing.

This has been my experience. Your results may vary.

View attachment 2061627

I reload some oddball and old calibers. Some of that brass has been reloaded 50+ times. I anneal the case mouths at least every third loading. These are mild handgun loads, but I have not had any issues with the brass. DR

 

[Xmark1]

Unnecessary to quench brass.

 

[P7M13]

In terms of Brinell hardness, water quenching yellow brass after heating may make it harder, but in terms of cartridge hardness, it achieves the desired effect - minimizing crystal formation. Work hardening - firing, sizing - promotes crystal formation. Crystal size becomes smaller with increased work-hardening, and the smaller brass crystals increase the likelihood of case cracks. The brass will be more brittle.
Over tens of thousands of annealed cases, I found there is no perceptible difference between water or air cooling in my brass. Hence, I no longer waste time in drying my brass.
Annealing brass is one of those things where YMMV applies. Eric Cortina did an experiment where he grossly over-heated his brass while annealing, and found it did not affect accuracy.
I anneal because the cheap bastige in me prefers more brass life, I like how my bullet seating force seems more consistent, and I want to believe it makes my hand loaded cartridges more accurate. But, accuracy is a funny thing - with the same load batch, some days I'll shoot 1/4 MOA, and on others I'll struggle to keep it under 1MOA -- that indicates that my annealing has a miniscule effect. Hence, while I anneal, I don't sweat the details too much.

 

[ActBlueDonor]

Spoken like a true Democrat!

Careful. Teslas quiver in your presence.