Hand annealing brass

G.O. West,

I think your old article is just bad. When Hatcher tried to blow up an early Garand to see how strong it was, he couldn't do it because case heads kept letting go first, gas cutting bolt face perimeters and blowing out stocks and magazines. So he had some special brass made with the headstamp struck extra deep to increase the work hardening so it would hold up until he got enough fast powder in a cartridge to actually burst the receiver and barrel.

Work hardening of the head matters and is a safety feature. You do not want to stress-relieve your case head. Even if the case doesn't let go, primer pockets will get loose early. This is why none of the commercial or military brass you see with annealing stains left intact show any stain much below the shoulder and the head and lower body receive none.

As to stress relief, if you look at the chart I put up, you will see serious stress-relief starts at 250°C (482°F), and finishes at 300°C, or 572°C in the one-hour time frame. You can get oxide just fine without getting there if you leave the brass in the heat long enough. It is an indicator for fast annealing processes, but it's not much use for the oven time frame. If I assume your oven's thermostat lets it run up and down around the control point some, you are probably getting to the bottom end of the range and just starting to stress-relieve. If you switch to one of the other methods described, you will get much more complete stress-relief and probably cease to see splits at all. But I would stop letting the head get hot. That's courting disaster. If you've ever seen a rifle whose case head let go, you'll recall a splintered stock and mangled magazine and magazine floor plate like Hatcher saw, and sometimes a mangled shooter to go with.
 
Unclenick

I cannot argue with your facts and logic. But what I can say is that I have been shooting this .450 Alaskan with these same heat treated brass cases for about 40 years now. 400 gr. Speer at 2150'/sec. is my favorite load. I have hundreds of these Winchester cases and many have been fired numerous times and heat treated my way before fire-forming, after fire-forming, and then after every fifth time fired. The primer pockets are as tight as new, the neck tension is perfect. None have yet developed any signs of incipient head separation. Maybe it's the lower than modern typical cartridge PSI, maybe it's something else, but it sure works great for me. I don't, but I could, get away with just neck resizing since I can easily re-chamber the spent cases. (When I was a profession guide I used it for my back-up gun and I never wanted even the slightest possibility of a tight chambering in grizzly country.) What else can I say? Perhaps you are right that it could be dangerous for every other cartridge out there. But I think I have proof tested it pretty well for my rifle (Win. #71), my cartridge, and my load.
 
Yosemite Steve asked:
Does it have to be mechanized to be reliable?
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No.

If you look, you can find several youtube videos of people with their home-made annealing machines that, for all their effort are either 1) having no effect on their brass or 2) are destroying it.

But, any hand method requires both some knowledge and some experience. I would recommend you invest in a 650 or 700 degree temperature-indicating paint (like Temp-i-laq) and use it while you get a sense of just how hot the case neck needs to get, what it looks like when it does and how long that takes.
 
Depending on the composition of the brass alloy,

Brass is chrystaline in nature and fragments as the brass work hardens.
Slivers broken of the chrystals wedge themselves in and stress ('Harden') the brass.
The slivers will eventually pry the grains apart & start a crack, just like a wedge splits concrete or wood.

Around 450*F the stress relieving starts, grains expand SLOWLY and either crush the slivers into 'Dust' or break off the sharp points.

Around 680*F to 730*F you will start to see absorption of the slivers & dust back into the chrystal grains, depending on formulation of the alloy components.

730*F to just under 800*F, and given enough TIME AT TEMPRATURE, you will start to see grains fully absorb dust & slivers and grain structure re-form to almost unused condition.

At above 800*F...
You start to loose the defined lines between grains, this is where you can go wrong VERY QUICKLY.
Grains start to absorb each other, headed towards huge grains which tear apart along separation lines.

Torch guys want 'FAST AT ALL COSTS' most times, so they use a super hot, oxygen gorged 'Jet' torch...
These torches often heat the brass TOO QUICKLY,
Any hesitation and at the very least, the outside of the brass wildly overheats.
TIME is a factor here, the brass has to have TIME for the process to work.
'FAST' isn't always 'Better', or in this case, correct.

Putting the brass in the hottest part of a 'Jet' torch is quick, but the results are somewhere between poor & spotty.
Back the torch up a little, let the heat evenly distribute, and you will have MUCH better results.
Keep in mind you are heating from the outside to the inside, and the thermal transfer takes TIME to happen.

Secondly, keep in mind the tip of that flame cone on a jet torch is VERY HOT, way too hot for the application.
You are hoping to limit temps around 750*F, so a 1,500*F (or hotter) flame isn't always the best choice...

Backing the torch up a little lowers the overall temp at the brass making controlling the top temprature reached much lower & much more controllable.
This gives MUCH more consistent results.

If you see a 'Glow' in the brass, particularly inside the case neck, it's hopelessly overheated, more often than not ruined.
It will still 'Shoot', but you have burned out (vapored off) components of the brass alloy.
Most torch flames change color when components of the alloy start to vaporize, so sometimes you can actually see the brass being ruined...

If you find a video of large factory flame annealing, you will notice they use fan tips, NOT oxygen engorged 'Jet' tips.
You will see a row of lower temp flames as the brass rolls through them OVER TIME.
This produces a very consistent, repeatable result even after several machining processes.
Lower heat, rotate the case for slightly longer time let's you reproduce what the factories have done for a century, with little chance of ruining the neck or sidewall of the brass.

Electro-magnetic induction annealing works differently, exciting the grains internally, so the entire brass heats evenly, from within, so it's faster, but it's also more expensive and difficult to do.
The 'Average' home reloader can achieve very good results with flame heating at very little cost. Higher production rates, or absloute 'Perfect' grain structure takes a crap load of equipment to do and a cubic ton of education in metallurgy, and reloaders don't actually need 'Perfect' or even a pre-designated grain size/particular structure to get excellent results.
Usually, get it up to 730*F, stay under 800*F, keep the head under 450*F and your brass will turn out pretty close to 'New' condition (Structure wise).
They were doing this 100 years ago, some places still use flame annealing and it still works!

This is as close as you will get without mounting & preparing lab samples of the brass and examining them under a microscope, buying a full scale hardness tester, etc.
 
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I cannot argue with your facts and logic. But what I can say is that I have been shooting this .450 Alaskan with these same heat treated brass cases for about 40 years now.
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The word that was coined to describe this situation is called "Normalizing Deviation"

Heat wise you are on the ragged edge of messing with the critical heat treatment of the case head. At worst what you can do on the far end is too soft, it won't go boom.

On the head end its a whole different story.

There is no logic involved here, its all fact.

A thermostat on the oven that shifts values could do you in, change of brass.

You know the risk, ok if you want to go there. Affecting others is a different story.

I would strongly suggest you not recommend that method again.

I am surprised it has not been stricken from the record. At the least tagged with a red flag warning.
 
I can't see a cookie sheet turning out well, along with the guy screaming 'RED HOT'!

There is basic science here, basic metallurgy...
At 450*F in an oven is BARELY doing anything to the brass, some slight stress relieving at the very most.
Most low temp stress normalization is often done in 12 to 24 hour cycles, so I can't imagine an hour doing much of anything unless the thermostat is WAY off...

Any hotter in the oven and you are risking softening the case lower walls and head, risking expansion in primer pocket, or even a case blowout under even reasonable pressure loads.

Heating to 'Red Hot!' is ruining the brass outright.
At 'Red Hot' much of the brass alloy components have long sense departed, the brass is pitted and has a silver color from the zinc leaching out.
Under normal metalurigic magnification, you are going to see one poorly defined 'Grain' left since it's absorbed everything around it.
It's soft all right!
Watch for the tear between poorly defined grains since they don't interlock anymore the grains tear apart easily and the brass fails.

Mono-chrystaline, one or two large grains at magnification, which is a scientific standard.
Micro-chrystaline, grains/chrystals broken to the point you can't really get a good count or see defined grains under standard scientific magnification.

It seems the old wives tales go from one extreme to another!
 
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G.O. West,

Jeephammer is correct that you are so close to doing nothing to the work hardening that I think you are probably just barely taking the edge off of it. When I did a time v temperature plot on our home oven a couple of years ago after I replaced the controls, I found it overshoots the setpoint by about 50 degrees as it comes up to temperature initially, then drops to the setting about 20 minutes later. I am wondering if the degree of strain relief you see is from something like that. It could also just be control hysteresis, bumping up and down, in and out of the relieving temperature range.

Whatever is going on, the fact you said you don't stop all the cases from splitting means your not getting full stress relief. Then the fact that you are probably working at pressures not over 40kpsi in the 450 AK is keeping you from seeing the worst effects of letting the head soften with the rest.

It's not very classy, but try the candle method on enough cases to satisfy yourself that you can get to 100% survival with a more controlled method, and then follow those cases to see how they endure.
 
My finger twisty torch and quench method made brass that had a less than 10 fps deviation into 20-95 fps deviation. 24 casings recycled. Lesson learned. After all the reading, I think it's only worthwhile to anneal under perfectly controlled conditions. It's way to easy to spoil consistent supplies. Considering what it takes to get single digit deviations... not worth it to me.
 
Back in the dark ages that's how I did it.
Another was holding the neck and shoulder in a small pot of molten lead, when your fingers started feeling the heat, remove the case , tap the neck on the pot to knock off any lead and drop into water.
Low tech as it was....it worked just fine.
Gary
 
Hay Bill DeShivs
That was a cheap shot on a interesting read . I never heated the necks of my brass , I get 25+ reloads out of the 30 cases used in 25+ range trips per season. I have plenty once fired brass to last me a lifetime shooting the amount of rounds I'm shooting . I load on the low side 40.8 of IMR 4064 under a 168 gr Sierra MK .What is the amount of reloads to shoot without heating the necks?
 
Considering what it takes to get single digit deviations... not worth it to me.
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it takes a lot more than annealing to get into the singe digits. Single digit SD's are an accumulation of many details each producing some small improvements which added together equals a big improvement in the end. Consistent neck trims, annealing , chamfering, primer seating depth and the most important thing of all precise charges of the right powder

But unless you are shooting for precision at long ranges or just enjoy the process of producing precise ammo it really is not worth the time
 
it takes a lot more than annealing to get into the singe digits. Single digit SD's are an accumulation of many details each producing some small improvements which added together equals a big improvement in the end. Consistent neck trims, annealing , chamfering, primer seating depth and the most important thing of all precise charges of the right powder

But unless you are shooting for precision at long ranges or just enjoy the process of producing precise ammo it really is not worth the time
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What I meant was that I already had single digit deviations and I destroyed that by my finger twist annealing.
 
so you managed to hold a case in your fingers long enough to get it overheated.... that is impressive
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If you hold it at the head... the heat moves down pretty slow. I only heated the neck and shoulder... using a propane torch.
 
My finger twisty torch and quench method made brass that had a less than 10 fps deviation into 20-95 fps deviation. 24 casings recycled. Lesson learned. After all the reading, I think it's only worthwhile to anneal under perfectly controlled conditions. It's way to easy to spoil consistent supplies. Considering what it takes to get single digit deviations... not worth it to me.
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It does not have to be perfect, but it does need quality controls built in.

Close is good, shoot for shy of perfect and its doable.

While the induction method is on the costly side, it also allows close tests and monitoring of the process (its exposed, no uneven heat, glow in dark checks easy)

I push them past right so I have a feel as to how far up the scale bad is. Sacrifice a few excess to get the feel of it all.

Often not that as I test with pickup brass I don't reload. Or I have a damaged case I can use etc.

The problem with the heat till your fingers get toasty is its only one part of the quality you are after (the most important part in not over heating the head)

It does no ensure the other end is not heated up past the right point.

The candle works because its got a fixed heat capability, then (apparently) it can work.

I still find it hard to believe people would do it that way. You can only burn your fingers so many times and they loose feeling.
 
If you hold it at the head... the heat moves down pretty slow. I only heated the neck and shoulder... using a propane torch.
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I tried the finger holding exactly once..then I picked up a drill and chucked up a socket extension and that was the end of that experiment. I continued to use the drill/socket/torch method for years the went auto. Combined with a lot of case prep I can hit singe digits on occasion but mostly stay in low teens and am happy with that. Sorting case's by volume and weighing bullets got old fast so I normally skip over that
 
Sorting case's by volume and weighing bullets got old fast so I normally skip over that
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If you use a digital scale and keep all the head stamps the same the volume will be the same. Every time I test that it's withing .2 grains. It takes me about an hour and a half to weight sort 100 rounds. I put them in a 100 round box and put them in weight order. Single digits is so much more reliable to load if you are testing for nodes. Zosler brass comes that way in the box. Worth every penny if you can afford it.

I will eventually make an annealing device and will test and calibrate it when I do.
 
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