Annealing...

[BCB]

Don't know where to put this question...

But, can one anneal brass by simply heating it and letting it air-cool...

OR must it be cooled quickly by putting it in water after the neck has been heated?...

Thanks...BCB

[s mac]

Look at my thread on the next page,Question on Annealing, I got some good info. I don't know how to give a link,.

[Love Life]

You can air cool as long as the case head doesn't get to hot. I like to water quench in water with citric acid as it removes any scaling and majority of coloring. The brass looks like it was never touched with a flame after you tumble...

Get some tempilaq. 750 degree for inside the case neck, and 400-450 for the bas of the case. Apply to a couple pieces of brass, run them trough the torch, and see how fast the heat transfers and how hot. If you can reach the 750degrees without the 400-450 tempilaq turning when air cooling then cool. If not then quench. To be honest I would just quench it anyway.

[KAF]

If brass is heated to 750* it then is not any good, way to soft and some of the good alloy is gone.
Heat to where there is only a slight blueish color, Air cooling is sufficient.

http://www.6mmbr.com/annealing.html

[Love Life]

That article says 750 degrees for a few seconds is legit.

The trick is to heat the neck just to the point where the grain structure becomes sufficiently large enough to give the case a springy property, leaving the body changed but little, and the head of the case virtually unchanged.

"If cases are heated to about 600 degrees (F) for one hour, they will be thoroughly annealed--head and body included. That is, they will be ruined. (For a temperature comparison, pure lead melts at 621.3 degrees F).

The critical time and temperature at which the grain structure reforms into something suitable for case necks is 662 degrees (F) for some 15 minutes. A higher temperature, say from 750 to 800 degrees, will do the same job in a few seconds. If brass is allowed to reach temperatures higher than this (regardless of the time), it will be made irretrievably and irrevocably too soft."

[ElDorado]

If brass is heated to 750* it then is not any good, way to soft and some of the good alloy is gone.
Heat to where there is only a slight blueish color, Air cooling is sufficient.

http://www.6mmbr.com/annealing.html

When he describes the actions of his machine-

"With this setup, the neck will actually reach a temperature between 750 and 800 degrees. Remember, it's the combination of time AND temperature that does the job. We have raised the temperature sufficiently to be able to anneal the case necks in 6 to 8 seconds."

[jonk]

If I had a fine machine like the one on the 6mm bench rest site, where I was sure heat was even and consistent, bases were in a heat sink, well then I would anneal my brass quite regularly.

As it is: It's hard to get a consistent even heating unless you use heat control paste. Uneven heating leads to uneven bullet release or if you overheat, crumpled necks. So I anneal: -black powder cartridges for my Henry 1860 repro; it's a real pain to clean out the action of black powder fouling, and the softer necks help seal things up. -Oddball brass I don't want to lose, as it is pricey- 11 mm Mauser, 8mm Kropatschek, that sort of thing.

Otherwise I don't bother. With 30-06 brass and stuff, when the neck cracks, it either gets reformed to another cartridge that is shorter with the same head size, or if that's not possible, put in the bucket for recycling.

[BattleRife]

If brass is heated to 750* it then is not any good, way to soft and some of the good alloy is gone.
http://www.6mmbr.com/annealing.html

This is not really true, and the linked article does not say any such thing. They do say that 950F will make the cases too soft, but I'm not sure I buy that, either. I see no mention of references in that article to suggest the temperature numbers they use are anything other than guesses they pulled out of thin air. Most of them appear to be based on ASM Handbook type data, all of which was generated in laboratory furnace experiments involving 1 hour annealing tests. As the article touches on, annealing is time-temperature dependant and 1 hour data doesn't mean much to those of who anneal for seconds.

I did an experiment where I severely work hardened the necks of some .308 Win brass, annealed them at various temperatures for 5 seconds, seated a bullet and placed them in a sealed plastic pail with a little water and ammonia-bearing Windex. The work hardened case necks started cracking, as exected, Those cases annealed at 400C and lower cracked within 60 days. Those annealed at 450C or above did not. Therefore I consider 450C (840F) the minimum temperature for annealing brass cases. I usually aim for the range of 500C-550C for about 4 seconds. That is 930-1020F. I have seen no evidence that my brass is "too soft".

96235

[Scharfschuetze]

Nicely done experiment BattleRifle. Quite illuminating in regards to the visual differences in annealing temperatures and the efficacy of the different temps.

While I have no idea what temperature or flame duration Lake City used/uses to anneal their cases, this M118 match load shows a distinct annealing ring below the shoulder that is similar to your 550 temp round above. While this is the older match round, current M80 Ball and M118 Special Ball and M852 Match 7.62 rounds all show this same annealing line and it is very consistent from round to round. It is also seen on the full range of 5.56mm and 50 Cal rounds produced at US arsenals.

I believe that US commercial ammo would also show this or a similar annealing ring were it not polished after annealing.

[Love Life]

Very good read and experiment BattleRife. I anneal using MAPP gas and 750F tempilaq. I get the same coloration on my brass as your 500C annealed brass. My current .243 brass is on 10 reloads with two annealings.

Interesting indeed.

[C. Latch]

I'm curious: I've been wanting to learn how to anneal and experimented some this weekend (too cold to shoot) with a torch, cordless screwdriver and sockets, and some brass that I had culled while sorting. Most of it was going to be thrown out anyway.

I purposely heated a couple of pieces to bright red, just to see how long it took (used .17hmr cases, couldn't do anything with them anyway). I was surprised at how long that took.

I then heated several cases until I just began to get a color change - a very light blue discoloration. Nowhere near glowing. When I later rinsed them in citric acid they came out with the 'annealed' part (top 3/8") more pink than the rest of the case. I assume that's a sign that I did something - leaving some zinc on the case surface, I suppose - but how do I tell how much I did?

I did several cases this way then belled them in an expander die, and noticed that they went into and out of the die with very light (i.e. hard to feel) pressure.

Apart from using tempilaq, do my result sound normal? The cases that I wanted to save, they did NOT turn red, even for a moment. For someone just learning, should I load them with light loads and fire them just to make note of how easily they expand to seal the chamber?

[ElDorado]

Light loads probably won't expand the cases.

Did you read the article in KAF's post? It's got a lot of good information. I now use tempilaq, but I have used the method described in the last two paragraphs of that article (the part that Rich DeSimone wrote) with fairly good results without tempilaq. Be sure to be in a dark room, at night, if you try it. I didn't use CLR, either. I either dropped them in water or air cooled them, depending on my mood at the time.

[C. Latch]

Did you read the article in KAF's post? It's got a lot of good information.


Multiple times over the last several weeks while contemplating this. It's the first link that shows up on any search of annealing brass.

I've read tons of stuff, but there are people in this thread who seem to have a degree of disagreement with the articles I've read, and I wanted to hear both sides.

[Doc Highwall]

One of the reasons you get a disagreement is what is the purpose of the person doing the annealing. Some of us just want to extend the life of our brass and are not interested in accuracy only case life.

Others are interested in accuracy formost and how annealing affects consistant bullet pull/start pressure and it's affect on accuracy. Accuracy is going to require a more involved set up that is repeatable using a dedicated annealing machine.

[BCB]

O.K.

I started this thread and I am getting some answers...

Now then, if I can take the brass and push the case mouth again something hard, with reasonable pressure and not brute force, and the mouth bends, is the brass TOO soft--TOO much annealed? (Is that a word?)

Thanks...BCB

[runfiverun]

the trick is to not burn out the zinc.
all annealing does is re-align the molecules in a more forgiving way so they can retain flexibility without tearing the base components apart.
time is not a factor in annealing brass, temperature is the deciding factor, 800-f is 800-f,
it don't matter if it's for 1 second or 10.
I strive for the look in the picture above, i use an annealing machine [and air cool] but don't use temp-Ilaq or anything else as an indicator.
I judge results by the finished products looks and performance.
I count on each case having the same amount of anneal rather than the exact perfect temperature.

[felix]

Actually, it's the time under the temperature-time curve which provides the amount of anneal. But, that is a lie also. Accuracy depends on the brass to be exact in all dimensions, including thermal. The lie comes into play when anealing brass in an unknown state. BR folks (in the know) do not anneal; they use brand new cases after about 10 shots or so. ... felix

[ElDorado]

O.K.

I started this thread and I am getting some answers...

Now then, if I can take the brass and push the case mouth again something hard, with reasonable pressure and not brute force, and the mouth bends, is the brass TOO soft--TOO much annealed? (Is that a word?)

Thanks...BCB

I don't know if there is a way to test your cases to see if they are too soft. I always try to stick to the guidelines of annealing at 700 - 800 degrees F and if they look similar to Sharfshuetzer's photo of match ammo, then I'll use them. If the necks don't split, then I've met my goal.

I have a 35 Remington and a 6.5 Carcano that have case splitting problems, and those are the ones I anneal most. I have annealed a lot of 30-06 to help when converting them to other cartridges. And it doesn't hurt to take any extra cases you have and practice and experiment, just remember to crush your experiments in a vise so you or someone else doesn't load questionable brass. I also like to make sure the cases are clean with no lube or other matter on them.

[ElDorado]

Multiple times over the last several weeks while contemplating this. It's the first link that shows up on any search of annealing brass.

I've read tons of stuff, but there are people in this thread who seem to have a degree of disagreement with the articles I've read, and I wanted to hear both sides.

As far as the pink in the annealed area after cleaning, I'm not sure. I know I've had cases turn pink during cleaning experiments, and it's usually a case that is brown with patina that's been soaked in vinegar or phosphoric acid. I've heard that the pink is a result of the zinc leaching or corroding out of the surface of the brass, leaving a visible layer of copper. I don't know if that's true, I'm just passing on what I've read.

And I don't know if testing your brass with a flaring tool will tell you much, since there are so many variables that can affect that. A soft case, a thin case, and even a short case will take less effort to flare than normal.

Like I just mentioned to BCB, I don't think there is a test that the average guy can perform that proves his annealing method is sound. The results will be seen when your cases stop splitting, or when you squeeze that 270 brass into an 8 mm.

[C. Latch]

As far as the pink in the annealed area after cleaning, I'm not sure. I know I've had cases turn pink during cleaning experiments, and it's usually a case that is brown with patina that's been soaked in vinegar or phosphoric acid. I've heard that the pink is a result of the zinc leaching or corroding out of the surface of the brass, leaving a visible layer of copper. I don't know if that's true, I'm just passing on what I've read.

And I don't know if testing your brass with a flaring tool will tell you much, since there are so many variables that can affect that. A soft case, a thin case, and even a short case will take less effort to flare than normal.

Like I just mentioned to BCB, I don't think there is a test that the average guy can perform that proves his annealing method is sound. The results will be seen when your cases stop splitting, or when you squeeze that 270 brass into an 8 mm.

Thanks!

Based on what I'm reading, I'm confident that I'm headed in the right direction here. I'd *like* to be perfectly consistent, but realize that isn't going to happen.

I currently only actively load for two rifles and I don't shoot either of them enough for this to be an issue right now, nor do I forsee shooting any other rifles in the near future to the point that annealing cases becomes an issue.

The main caliber I want to work with is .45 Colt. I know brass can last a long, long time, but I have some loads that I crimp HARD and I know that'll kill my case mouths. I also know that if I get the brass too soft I'll lose the tension I need for consistent ignition. I suppose that at the end of the day, I've read all I need to read; I won't know anything else until I get some annealed cases loaded up and shoot them and see what happens.

[C. Latch]

Well, I shot a handful of the annealed cases today; no problems, but I was shooting light load that isn't terribly dependent on consistent crimps.

When these cases dry out and I can reprime them I'm going to load a hotter, slower-burning load and see how they fare when crimped hard.

[GaryN]

Anybody try the lead dipping method. I haven't but was wondering about it. I thought maybe you could use pure lead to keep it from sticking to the brass and then drop it in a bucket of water after a few seconds. You would have to dry them out after but it did seem to be an easier way. You could also easily repeat the process on each piece of brass keeping the temp. the same.

[C. Latch]

repeat the process on each piece of brass keeping the temp. the same.


I don't think that process would be any more consistent than spinning a case over a torch flame; the torch flame is pretty consistent temperature and if you develop a cadence whereby you count out X seconds then drop the case, the only major variable in temperature consistency would be in how much variation there was in your case neck thicknesses.

I could be wrong though.

[leftiye]

Chucking the case in a drill motor and turning it in the flame should work (and solve any flame frome one side issues) if you get the time/temp right - tempilaq should solve that part for you. I don't think the issue has much to do with the hardness before annealing, ie the results should be the same regardless. Over-doing it ain't good, I've heard, though I'm sure that I've overdone a bunch and they shot just fine. The tempilaq should avoid that anyway. Too soft will self correct as the brass work hardens (unless you burn the zinc out of the brass), consistent softness between cases in same group/load is what's important, not what the specific hardness is.

Lead dipping should solve all of the inconsistency issues of a flame from one side. Dipping neck and shoulder in lead of About 700 degrees should avoid most of the issues of over or under annealing. Results can be assessed, and temp/time can be adjusted to your preference. Dipping case mouth and shoulders in synthetic two stroke before putting case into lead should obviate lead sticking (use tongs and gloves to avoid any spatter, and time each dip). There may be other things that you can dip into that work better, but bull plate lube should do it. You can hold the case in your fingers to tell when the heat is soaking up towards the case head, and toss it into water at that point (be sure to test for spatter with your oil before getting your fingers that close).

[s mac]

After reading about the lead dipping method here on the forum I did try a short run, it seemed very effective. don't forget to leave a spent primer in place.

[hickfu]

Wow, I thought I had the annealing thing down pretty good before I started reading more on Annealing..... I have only done straight walled 45-70 cases so far but I just put them in the socket that I have set so they are at a certain height and hit them with the propane tourch while spinning for a slow count of 3 (one thousand one, one thousand two, one thousand three) and drop them into the water, I then use a thrift store bought dehydrator to dry them completely.... They seem to work pretty good that way but then again its a 45-70 and not a sniper rifle where it is REALLY important to get things perfectly the same every time.

I use new Starline brass so it needs to be annealed or it wont seal the chamber.


Doc

[BattleRife]

I don't think that process would be any more consistent than spinning a case over a torch flame; the torch flame is pretty consistent temperature and if you develop a cadence whereby you count out X seconds then drop the case, the only major variable in temperature consistency would be in how much variation there was in your case neck thicknesses.

I could be wrong though.

I'm going to say you are wrong. According to Wikipedia, the temperature of a propane/air flame is about 2,000 C ( call it 3,600 degrees F) hotter than our target temperature for annealing. With that kind of temperature difference, the energy transfer rate to the case is very high and a steep gradient can be expected through the case wall and around the case circumference. Temperature of the brass is likely rising at something like 100 deg. C per second. A machine can be set to produce fairly consistent methods, but a batch annealed by a human being would almost certainly have an annealing temperature range of close to that 100 C number.

I anneal in molten salt. It's like annealing in lead, but the salt dissolves as soon as it's dropped in water. I set the temperature of the bath to my target temperature for annealing. I can control the temperature of the bath within ~8 deg C without any controller other than the temp dial that comes on the Lee Melter, and it doesn't matter if I immerse the case neck in the bath for 5 seconds or 20 seconds, the neck is heated to the target temperature, at all points around the neck. No flame annealing process can even come close to the foolproof consistency of an immersion bath.

[leftiye]

Battle, I'm going to say that you're wrong. If one uses tempilaq, then temp is reached, not overshot, and heating terminated (drop, or drop in water). Rate of spin can easily be controlled by drill motor. Remember that flame plays on one half of case. Rapid spinning should be very even heating. Using a small flame at a moderate distance should avoid radically high temp rise rate.

On the other hand I do like the hot liquid dip method a lot (to include lead). By salt do you mean NaCl? Borax is liquid at (lead) melting pot temperatures too, and is useful as an oxygen barrier to steel annealing temperatures. Harder than bejeesus to get off (no dissolving) though.

[C. Latch]

I doubt the 100' C per second rise in temperatures (it would be highly dependent upon flame size; thus far I have ran a very small flame) as it takes me 6-8 seconds to show signs of a 300' C or less rise in temperature, but I've never heard of this molten-salt method and would be interested in hearing more of it.

[popper]

Lead dipping works fine. It's NOT NaCl. Covered in the annealing thread.

[BattleRife]

Battle, I'm going to say that you're wrong. If one uses tempilaq, then temp is reached, not overshot, and heating terminated (drop, or drop in water). Rate of spin can easily be controlled by drill motor. Remember that flame plays on one half of case. Rapid spinning should be very even heating. Using a small flame at a moderate distance should avoid radically high temp rise rate.

On the other hand I do like the hot liquid dip method a lot (to include lead). By salt do you mean NaCl? Borax is liquid at (lead) melting pot temperatures too, and is useful as an oxygen barrier to steel annealing temperatures. Harder than bejeesus to get off (no dissolving) though.

In theory the Tempilaq should be a reliable indicator of target temperature, but the problem is the reaction time of the person. I know when I anneal in a torch flame heating time is probably less than 4 seconds, which is why I estimated 100C per second. At that kind of heating rate the typical human reaction time of 0.2-0.3 seconds makes a difference, and rarely a consistent one.

My salt bath is potassium nitrate. It is mentioned in the annealing sticky in the reloading tools section.
http://castboolits.gunloads.com/showthread.php?153620-Annealing-Setup

[C. Latch]

http://castboolits.gunloads.com/showthread.php?153620-Annealing-Setup


Thanks for the link. I'll have to say, that's about as neat a setup as I could imagine. If I ever get to the point of having a dedicated reloading room, I'll have to try that. Until then, the propane torch on the kitchen table will have to do.

[dtknowles]

I have been using a torch and my .22 hornets get bare finger twisted in the flame for a 10 count then dropped in the water. The seem to be annealed properly. They don't seem too soft.

Tim

[Big Boomer]

For a long time I tried to figure out how to use a propane torch effectively on the side of rifle cases deprimed and sitting in a pan with about 2/3rds of the case in water. It looked to me like only one side was getting the heat treatment, i. e. unevenly. Always did the annealing in the dark so I could see better what was happening to the cases. Then I tried bringing the torch flame straight down into the mouth of the cases, holding the flame about the same distance each time (everything else as above) and things seem to work fine. Since I don't shoot as much as I used to, annealing the cases in small batches as described seems to work okay for me. Rarely lose a case for any reason. For those that shoot a great deal but still desire max accuracy and can justify the investment, the automated system would be the way to go. Big Boomer

[C. Latch]

I shot two different guns with my annealed case today - first, the .45 Colt with some ruger-only (but not maximum) loads; case heads showed no signs of change but the mouths were very soft and extraction was very, very sticky. I blame that on the loose ruger chambers as much as anything - but the cases didn't crack, and they resized easily. They seem to be working OK.

Then I shot five rounds with jacketed bullets in my 30-06 using a near-maximum (but within published data) load of IMR4895. Five of them went into less than 1.5" at 100 yards, including the fouling shot from a clean, oiled bore. That's great for this particular rifle. Cases looked normal and showed no sign whatsoever of being overly soft.

[butch2570]

I did an experiment a few years back with this in a 222 rem ,where i took some brass that had about 4 or 5 firings on them and purposely heated the necks until they were blood red and water quinched them. The necks were pink and so soft i could take a finger nail and push the neck in,i proceeded to load those rounds the same as the other cases with no annealing and in that particular rifle the groups opened up about 1/2 to 5/8 more at 100 yds with jacketed, as i'm sure this was a neck tension issue and greater extreme spreads, but not near enough to hurt hunting accuracy for coyote /fox size game . I shot those cases a couple more times afterwards and had no failure in the neck area with them ,but that was NOT a max loads either,i couldn't really determine though if after being fired again if they were work hardening or not , if they were it was minimal. That was my experience and yours may be totally opposite.Again an experiment too see what would happen , not a recommended practice.

[giz189]

I shot two different guns with my annealed case today - first, the .45 Colt with some ruger-only (but not maximum) loads; case heads showed no signs of change but the mouths were very soft and extraction was very, very sticky. I blame that on the loose ruger chambers as much as anything - but the cases didn't crack, and they resized easily. They seem to be working OK.

Then I shot five rounds with jacketed bullets in my 30-06 using a near-maximum (but within published data) load of IMR4895. Five of them went into less than 1.5" at 100 yards, including the fouling shot from a clean, oiled bore. That's great for this particular rifle. Cases looked normal and showed no sign whatsoever of being overly soft.. C.Latch I experienced the same problem of sticky extraction with my 657 S&W 41 mag. I only annealed them once and continued using them and the sticky extraction went away. I quit annealing handgun brass after that.

[C. Latch]

. C.Latch I experienced the same problem of sticky extraction with my 657 S&W 41 mag. I only annealed them once and continued using them and the sticky extraction went away. I quit annealing handgun brass after that.

I think that from here on out I'll keep using these cases, expecting them to firm back up some, and won't anneal them again until one of them splits. But it's good to be able to say I've somewhat learned how to anneal brass.

[GP100man]

I know you fellers are talkin `bout rifle ,but here`s some 357 brass I heated to improve case life & accuracy .

I use a roll crimp on my straight walled revolver rounds & noticed some roll still there after firing so I annealed it a bit (experimenting showed this amount worked the best) to allow full release yet retain a consistent boolit pull

http://i746.photobucket.com/albums/xx110/GP100man/102_0510.jpg (http://s746.photobucket.com/user/GP100man/media/102_0510.jpg.html)

As you can see it is discolored very little but I can`t argue with results !

I also anneal rifle , & admit I don`t go as far as the 550 round, sorry no pics of rifle brass.

I`ll add +1 for experimenting then crushin the experiments .

[cbrick]

Actually, it's the time under the temperature-time curve which provides the amount of anneal. But, that is a lie also. Accuracy depends on the brass to be exact in all dimensions, including thermal. The lie comes into play when anealing brass in an unknown state. BR folks (in the know) do not anneal; they use brand new cases after about 10 shots or so. ... felix

Felix is right! Ok, "felix" and "right" in the same sentence is redundant, when isn't he right? :mrgreen:

I've played with the annealing quite a bit. The picture of the BC-1000 in the 6BR site annealing article (the same article is also on my web site, lasc.us) is my picture of my annealer w/357 shell plate taken on my glass patio table. So why is felix right? Because if I learned anything about annealing it's that it is an art form that very few people actually get right consistently from batch to batch, even with the very best of automated equipment such as the BC-1000. If your goal is simply brass life for hard to get brass it works and will extend brass life. If your goal is match accuracy and you understand the difficulty in consistency from batch to batch you will do as felix said . . . Use new brass, not annealed brass. The BC-1000 does an excellent job of consistency within any given batch of brass, the trick is to get that same anneal on the next batch and the next one and . . .

I worked pretty hard at learning, or trying to learn to get good consistency from batch to batch but my long range handgun scores suffered. Using the same annealed brass each firing would have different group sizes and different sight settings each time it was annealed. Going back to new brass and all was right in the world.

Obviously annealing works, if it didn't the manufacturers couldn't make the brass in the first place. New brass is annealed a few different times during it's manufacture to keep it from being work hardened. For the big matches in revolver class for the best possible anneal and consistency in work hardening I fired only virgin brass, trimmed to length, no F/L sizing, slightly expanded & belled for shooting boolits.

Rick

[Mk42gunner]

I am not an expert on annealing; in fact, I think I have screwed up more brass than I have saved or helped by annealing. With that said, I have read a lot about it.

Rick makes a very good point about the difficulty of being consistent from batch to batch.

In some book about reloading for BPCR, (I think it was the SPG Black Powder Loading guide); one of the guys in the back of the book stated that he annealed his brass and then resized and ran it over the expander twice to work harden the brass consistently, before loading his match loads.

It kind of makes sense to me, given that brass does work harden. It does sound like a lot of extra effort, and I am not sure I would want to do it for a 500 or 1000 round lot.

Robert

[leftiye]

So, a couple of sizings might produce better consistency than the annealing does of itself? A good thang to know.

[Doc Highwall]

With annealing you need the correct neck tension, too little and you are back where you started and too much and the groups can open up again. The neck tension is the second thing after the primer that controls the start pressure, with the bullets relationship to the rifling considered as another factor.

What needs to be controlled when annealing cases is the actual temperature and the length of time that the case neck is exposed to the temperature. The temperature is influenced by the pressure of the gas/size of the torch orifice and the distance from the case. How are you going to control the time duration to say plus or minus 1/10th of a second so that each time you anneal that the time is repeatable with any degree of accuracy. As soon as you have variables that are not controlled, you have an out of control process that leads to doubts about the process's true capabilities and fails to add scientific data that can be actually useful.

[BattleRife]

So, a couple of sizings might produce better consistency than the annealing does of itself? A good thang to know.

Actually, one thing to try would be a couple of aggressive sizings before annealing. This is because the rate of recrystallization of brass when annealed is significantly affected by the amount of cold work present in the brass at the time of the anneal. A heavily worked structure will initiate many more new crystals at a specific temperature than will a moderately worked structure. Once annealing is complete, this will result in a more finely grained structure. So, if your cases all have varying degrees of cold work, theory says the resulting structures will be inconsistent.

It's just my guess, but I suspect a couple of heavy sizings (say, expansion of a case neck up a caliber, then back down to where it should be) would result in enough cold work that the material recrystallization would be a lot more consistent from case to case.

[Doc Highwall]

BattleRife, I agree with what you said about different degrees of work harding negating the annealing process but, this is why I buy enough cases for a rifle that are only shot in that one rifle and all will have the same amount of firings when annealed. Any of the cases that are culled due to weight can still be used as barrel warmers or sighters to keep the firings all the same, or they can be culled for specific loads and kept separate when annealed.