Under annealing brass?
- Thread starter nddodd
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Well, not getting the brass too the proper temp acomplishes nothing.
There would also be no harm done, just a loss of propane and time.
I think there's a learning curve that requires botching at least some brass, I followed advice and started with range pick-up stuff till I got the hang of it. Seem's there is about 40 ways to do the task, and a full 20 of those are just plain wrong.
I like the dark room, dull red color method. Works for me. Ya just gotta get the gumshon up an try it. Good luck, it ain't really tuff, but again there is a learning curve.
There would also be no harm done, just a loss of propane and time.
I think there's a learning curve that requires botching at least some brass, I followed advice and started with range pick-up stuff till I got the hang of it. Seem's there is about 40 ways to do the task, and a full 20 of those are just plain wrong.
I like the dark room, dull red color method. Works for me. Ya just gotta get the gumshon up an try it. Good luck, it ain't really tuff, but again there is a learning curve.
Forum Boss
Administrator
We do not recommend the red color in dark room method because color is subjective so it is very easy to over-anneal and ruin your brass, particularly if you are holding the torch by hand. We recommend using a machine with a timer, with flame at fixed angle and distance, and carefully practice with appropriate Tempilaq.
Darrell Jones, who runs djsbrass.com, a cleaning/annealing service, has done extensive testing with cartridge brass. He warns that over-annealing can occur in a surprisingly short amount of time if you leave the case too long in the flame. Those who anneal manually must also be very careful about distributing the heat evenly on the neck and avoiding overheating the lower half of short cases.
Suggest you read this page: http://www.annealingmachines.com/how_to_anneal
Darrell Jones, who runs djsbrass.com, a cleaning/annealing service, has done extensive testing with cartridge brass. He warns that over-annealing can occur in a surprisingly short amount of time if you leave the case too long in the flame. Those who anneal manually must also be very careful about distributing the heat evenly on the neck and avoiding overheating the lower half of short cases.
Suggest you read this page: http://www.annealingmachines.com/how_to_anneal
I would like to see a clear definition of what "over annealed" really is. My suspicion is that most under anneal their brass and simply waste their time and propane. Or, worse still they partially anneal it and end up with varying degrees of brass strength, and they are worse off than they were when they started.
memilanuk
Gold $$ Contributor
My understanding was that if you 'under anneal' the brass i.e. get fairly close to the minimum temp that annealing takes place you may not get the true 'change' in the brass but you will still get some degree of stress relieving taking place. It may not be as 'good' as full-on annealing, but its a lot less likely to ruin your cases.
YMMV,
Monte
YMMV,
Monte
Have any of you ever used a lead pot? It would seem to cover everything:
1) Temperature easy to control wih thermometer.
2) Length of anneal time controlled by you.
3) Much faster speed. If you could find a way to do 2-3 at a time, even faster.
4) Cheap, especially if you already have it for casting bullets.
1) Temperature easy to control wih thermometer.
2) Length of anneal time controlled by you.
3) Much faster speed. If you could find a way to do 2-3 at a time, even faster.
4) Cheap, especially if you already have it for casting bullets.
BoydAllen
Gold $$ Contributor
A friend had a problem with his .338 Lapua, and Winchester 7mm WSM brass. There was too much variation in the amount of shoulder bump that a given FL die setting would produce. If we set the die on one of the softer cases, the bolt closed really hard on the harder ones. (Yes, we measured the bump, with the correct tool.) Thinking that the problem might be from inconsistent hardness at cases' shoulders, he bought a rotary case annealer, one that uses two torches, and which pauses the cases in the flame. It was featured in a video on this site, but is no longer available. Using the annealer, a test case, and three different temperatures of Templaq, we were able to set up the annealer so that the shoulder bumps were very consistent (.001 ES) and still preserve a decent amount of neck tension, which had not been a problem.
I am always concerned when I read directions to heat case necks to a slight glow in a darkened room. It may be that for certain applications that the soft necks that will be produced using this technique will give good accuracy, but in many cases accuracy will suffer, as it did for me when I tried this technique over 20 years ago.
The other concern that I have is that without some method of monitoring how hot the case heads are getting, or a water bath to limit head temperature, single torch, hand annealed cases may be dangerous in the extreme. The machines have the advantage of precise timing, and if a temperature indicating material is used for set up, will yield more consistent results, that are less likely to be hazardous.
I am sure that this post will elicit a response from someone that he has been making case necks glow, and tipping them them over into the water that they stand in for decades (no harm in the water and tipping) with good results, for a long time. Who am I to disagree? I am just reporting that when I did it, the necks were too soft, and while it did prevent case loss from cracking caused by work hardening, accuracy suffered, and the difference was not worth the savings from longer brass life.
IMO Ken Light has the best handle on how hot to get case necks. Anyone who contemplates annealing cases should Google him, and read his material. Good luck. Remember, if you get your cases' heads too hot, you WILL blow up your rifle, and very likely be injured, perhaps permanently.
I am always concerned when I read directions to heat case necks to a slight glow in a darkened room. It may be that for certain applications that the soft necks that will be produced using this technique will give good accuracy, but in many cases accuracy will suffer, as it did for me when I tried this technique over 20 years ago.
The other concern that I have is that without some method of monitoring how hot the case heads are getting, or a water bath to limit head temperature, single torch, hand annealed cases may be dangerous in the extreme. The machines have the advantage of precise timing, and if a temperature indicating material is used for set up, will yield more consistent results, that are less likely to be hazardous.
I am sure that this post will elicit a response from someone that he has been making case necks glow, and tipping them them over into the water that they stand in for decades (no harm in the water and tipping) with good results, for a long time. Who am I to disagree? I am just reporting that when I did it, the necks were too soft, and while it did prevent case loss from cracking caused by work hardening, accuracy suffered, and the difference was not worth the savings from longer brass life.
IMO Ken Light has the best handle on how hot to get case necks. Anyone who contemplates annealing cases should Google him, and read his material. Good luck. Remember, if you get your cases' heads too hot, you WILL blow up your rifle, and very likely be injured, perhaps permanently.
my best measure as to whether i've annealed properly and adequately is to spin the case in my vise mounted drill, use really hot butane torch and watch for the color change. briefly move the torch away, then back until the grey/bluish color appears and usually runs down the shoulder into the body and stops as the torch is removed. i look for the slight reddish-purple line at the juncture of the color change and the normal brass color, and compare with an unfired lapua case that has this beautiful reddish-purple line. i think i'm doing a good job since several experienced handloaders can't tell my brass from the lapua. i cool the cases on a steel plate that sits on one of those freezer packets that are put in coolers. polishing th case neck-shoulder-body aids in seeing the color change. practice makes perfect.
I agree with the forum boss. Red is not something I want to see unless I'm practising on scrap. I pulled "my method" out of an earlier post. No expensive machine or Templaq but I seem to have it down now. Pay particular attention to "the ring" I described. IMO thats the key.
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Annealing is a bit of an artform. Not very hard to learn if your willing.
If you have an old lot of scrap brass thats the best place to start.
Every lot of brass will require different times in the heat.
Different cartridges can require large variations in heating times.
Practice in the dark like you are. Intentionally overheat some and compare. When you can dent the case lips with your thumbnail you've gone to far. I count in cadence every cartridge. When I settle on a count they all get the same count.
I use a drill with a deep dish socket. For short/fat cases a little tinfoil wadded up in the bottom adjusts the height in the socket.
I now work in the daylight.
What I've noticed with all sorts of assorted brass is a blue/gray ring forms just outside the fire as the case is spinning. Shortly that ring will speed up and begin to move down the shoulders and body. When it reaches the properly adjusted socket that case is done.
For me that marching ring is the best indicator I've yet discovered.
It can be seen in the dark too.
I've also noticed the color of the flame on the opposite side of the case will change color and flare like sunspots. Burning carbon or zinc I'm not sure. Carbon OK, zinc not so good.
Its not a stable indicater of anything but I never want to go much past that point. Usually the ring and flares coincide nicely.
I never see any red in the daylight. Try for no red in the dark also. Its usually just a touch too well done if you see red.
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Last annealing I did was for my 30BR. Some cases were sticky even at low charges. Tried turning the necks a little more. No help.Started annealing. It actually took me three trys to properly anneal those cases simply because they were so hard I never had to leave any case in the heat so long. Did'nt want to ruin them. Shooting in between tries showed improvement but still some stick. On the third try that darn ring finally formed and marched down the neck.Cases haven't exhibited any stickiness since.
lpreddick seems to be looking at the same thing I see. Its the ring. ;D
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Annealing is a bit of an artform. Not very hard to learn if your willing.
If you have an old lot of scrap brass thats the best place to start.
Every lot of brass will require different times in the heat.
Different cartridges can require large variations in heating times.
Practice in the dark like you are. Intentionally overheat some and compare. When you can dent the case lips with your thumbnail you've gone to far. I count in cadence every cartridge. When I settle on a count they all get the same count.
I use a drill with a deep dish socket. For short/fat cases a little tinfoil wadded up in the bottom adjusts the height in the socket.
I now work in the daylight.
What I've noticed with all sorts of assorted brass is a blue/gray ring forms just outside the fire as the case is spinning. Shortly that ring will speed up and begin to move down the shoulders and body. When it reaches the properly adjusted socket that case is done.
For me that marching ring is the best indicator I've yet discovered.
It can be seen in the dark too.
I've also noticed the color of the flame on the opposite side of the case will change color and flare like sunspots. Burning carbon or zinc I'm not sure. Carbon OK, zinc not so good.
Its not a stable indicater of anything but I never want to go much past that point. Usually the ring and flares coincide nicely.
I never see any red in the daylight. Try for no red in the dark also. Its usually just a touch too well done if you see red.
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Last annealing I did was for my 30BR. Some cases were sticky even at low charges. Tried turning the necks a little more. No help.Started annealing. It actually took me three trys to properly anneal those cases simply because they were so hard I never had to leave any case in the heat so long. Did'nt want to ruin them. Shooting in between tries showed improvement but still some stick. On the third try that darn ring finally formed and marched down the neck.Cases haven't exhibited any stickiness since.
lpreddick seems to be looking at the same thing I see. Its the ring. ;D
spclark
Gold $$ Contributor
Time & temperature are the key elements, not how "tempered" the brass might be.
Thicker brass may take a bit longer but the temp requirement is the same as for thin-wall.
Burned brass - brass that's been overheated out of carelessness or ignorance - is unsafe. It'll look dark & kinda rough, not at all like new cases fresh from the factory packaging.
I use new Lapua brass appearance as a visual standard for my home efforts at annealing my fired brass. Five to seven seconds spinning about 60 - 80 RPM just outside the inner blue flame on a propane torch (inner flame's adjusted to 5/8' - 3/4" long) does it for the cartridges I shoot. Shorter time for .223 & turned 6mm, longer time for L/C unturned 308. Everything else is somewhere in between.
Anneal fired brass only after it's been cleaned, otherwise you'll have a harder time seeing the surface color change and you also may make carbon deposits harder to remove.
Thicker brass may take a bit longer but the temp requirement is the same as for thin-wall.
Burned brass - brass that's been overheated out of carelessness or ignorance - is unsafe. It'll look dark & kinda rough, not at all like new cases fresh from the factory packaging.
I use new Lapua brass appearance as a visual standard for my home efforts at annealing my fired brass. Five to seven seconds spinning about 60 - 80 RPM just outside the inner blue flame on a propane torch (inner flame's adjusted to 5/8' - 3/4" long) does it for the cartridges I shoot. Shorter time for .223 & turned 6mm, longer time for L/C unturned 308. Everything else is somewhere in between.
Anneal fired brass only after it's been cleaned, otherwise you'll have a harder time seeing the surface color change and you also may make carbon deposits harder to remove.
The issue I have with this whole subject of over annealing is that there is no definition that I can find of what that really means.
If you check the engineering specifications for cartridge brass you will find that annealed brass has a yield strength of 17,000 psi, and ultimate strength of 49,000 with an elongation of 57%. It has moderate strength and excellent ductility.
Cold worked brass on the other hand has a yield of 63,000 (stronger than some steel), ultimate strength of 76,000 psi and elongation of only 8%. In other words it becomes stronger, and more brittle.
The annealing temperature for cartridge brass is 800F to 1400F. Metals just start to glow red in a darkened room at about 800F. This is the very start of the annealing temperature range for brass. There is no way this temperature is too high, and is really just barely enough.
Annealing of brass is very different than tempering steel. Annealing is more of a yes no. It happens quite rapidly when you reach the annealing temperature. Tempering of steel on the other hand is very temperature dependent. The lower the temperature you temper at the less tempering is done. For that reason the strength of steel that has been oil quenched and tempered will have a tempering temperature as part of the specification. It indicates how strong the steel will be. Higher is more ductile and less strength, and lower is more brittle and higher yield. This is a very controllable and well used process for steel.
I have never seen any such thing for brass. It is annealed or it is not. You can go from annealed to cold worked in a very controlled manner. The more you work it, the stronger and more brittle it gets. This directly relates to the number of firings in a cartridge. However, I remain unconvinced you can go in the opposite direction with any kind of reasonable control. When annealing happens so suddenly I would suggest there is no way to control the outcome of some partial annealing process. My thought is that you either do not do enough and just waste propane and time, or you anneal it. The problem is that this can vary from case to case. You start with a box of work hardened brass, and after the process you end up with a box of brass that is a mixed bag. Some is annealed, and some are just as hard and strong as they were before.
Just my thoughts. Some data on cartridge brass can be found at this link.
C26000 Cartridge Brass
If you check the engineering specifications for cartridge brass you will find that annealed brass has a yield strength of 17,000 psi, and ultimate strength of 49,000 with an elongation of 57%. It has moderate strength and excellent ductility.
Cold worked brass on the other hand has a yield of 63,000 (stronger than some steel), ultimate strength of 76,000 psi and elongation of only 8%. In other words it becomes stronger, and more brittle.
The annealing temperature for cartridge brass is 800F to 1400F. Metals just start to glow red in a darkened room at about 800F. This is the very start of the annealing temperature range for brass. There is no way this temperature is too high, and is really just barely enough.
Annealing of brass is very different than tempering steel. Annealing is more of a yes no. It happens quite rapidly when you reach the annealing temperature. Tempering of steel on the other hand is very temperature dependent. The lower the temperature you temper at the less tempering is done. For that reason the strength of steel that has been oil quenched and tempered will have a tempering temperature as part of the specification. It indicates how strong the steel will be. Higher is more ductile and less strength, and lower is more brittle and higher yield. This is a very controllable and well used process for steel.
I have never seen any such thing for brass. It is annealed or it is not. You can go from annealed to cold worked in a very controlled manner. The more you work it, the stronger and more brittle it gets. This directly relates to the number of firings in a cartridge. However, I remain unconvinced you can go in the opposite direction with any kind of reasonable control. When annealing happens so suddenly I would suggest there is no way to control the outcome of some partial annealing process. My thought is that you either do not do enough and just waste propane and time, or you anneal it. The problem is that this can vary from case to case. You start with a box of work hardened brass, and after the process you end up with a box of brass that is a mixed bag. Some is annealed, and some are just as hard and strong as they were before.
Just my thoughts. Some data on cartridge brass can be found at this link.
C26000 Cartridge Brass
Larryh128 said:All of this got me thinking :Does it take longer to anneal brass that has been work harded by 5x firing vs 2x firing? Or is brass, brass regardless of the hardness? ???
I'd have to respectfully disagree with spclark. I also fully comprehend my opinion would go against all scientific logic. Just does'nt make sense even to me. ???
IMO the harder the brass the longer it will require heat to anneal.
The 30BR brass I mentioned previously (.0095 neck thickness) was heated for a fast count of 30 with a Mapp gas torch bought just for this brass. First two attempts were with standard propane.
My normal count for Lapua 308W (.015 necks) is 20. I'm fairly certain if I put my 308W in Mapp gas for a count of 30 it would be glowing and "dead soft".
I also suspect my 30BR brass will never require a long duration again, if ever.
I've seen it with other brass I let go and did not anneal regularily. just not as prominent.
Once again, can't explain it, don't really expect anyone to believe it. Just don't be shocked if you ever see it. ;D
Larryh128
Silver $$ Contributor
Ron,
Basically my thoughts although less acedemic on my part. Lot to lot & manufacturer to manufacturer there is definitely a time difference that I have seen. Very likely due to differences in neck thickness. Nice overview, thank you. Although we know that annealing the body is a no no, won't an "over annealed" neck simply harden? While accuaracy might not be there, I don't see the safety issue on the neck being too soft.
Basically my thoughts although less acedemic on my part. Lot to lot & manufacturer to manufacturer there is definitely a time difference that I have seen. Very likely due to differences in neck thickness. Nice overview, thank you. Although we know that annealing the body is a no no, won't an "over annealed" neck simply harden? While accuaracy might not be there, I don't see the safety issue on the neck being too soft.
spclark
Gold $$ Contributor
RonAKA what you state is quite true: there's little definitive info out there to rely on. Few if any of us have access to or knowledge about testing brass hardness of the cases we're using. The folks who make mechanical annealers probably know more about the technique and results than the average reloader. Brass & steel, two completely different metals; what works for one will not be appropriate for the other.
I started annealing cases because of the condition you speak of - a bag of fired brass exhibiting vastly different response to sizing. Ruining some cases initially - obvious overheating, accompanied by surface scaling & discoloration - taught me that less is more when it comes to both the size of the flame on my propane torch and how long I keep a case neck at the hottest point of that flame.
I refined my technique with the concept of improving consistency as I went along. What I've arrived at works very well for me now, I can do 100 cases in a little over an hour & they all size (shoulder bump & neck size OD) to within 0.0005" with a single die set-up.
Overheating of brass cases risks de-zincification. Zinc's melting point is at the low end of the temps necessary for annealing brass, it's boiling point is a little beyond the high end. Copper's MP is well above this so the risk in overheating is to the Zinc content and brass matrix. In an oxygen-bearing atmosphere Zinc will oxidize at room temperature over time. Oxidation accelerates at elevated temps.
There's a relatively simple test you can do to get an idea of the effect your annealing practices have on cases. Take three fired cases of the same type. Heat the neck of one for six or seven seconds in a propane torch. Heat another until it's bright, cherry red then keep it at that temp for a count of ten. Let both cases cool to room temperature.
Now take a pair of pliers & crush the necks of each case, starting with the overheated one. End up with the unannealed one. It's a crude experiment but worth your time if you'r just starting to deal with what it takes to anneal cartridge cases both to extend their useful life and to improve their response to resizing operations.
I started annealing cases because of the condition you speak of - a bag of fired brass exhibiting vastly different response to sizing. Ruining some cases initially - obvious overheating, accompanied by surface scaling & discoloration - taught me that less is more when it comes to both the size of the flame on my propane torch and how long I keep a case neck at the hottest point of that flame.
I refined my technique with the concept of improving consistency as I went along. What I've arrived at works very well for me now, I can do 100 cases in a little over an hour & they all size (shoulder bump & neck size OD) to within 0.0005" with a single die set-up.
Overheating of brass cases risks de-zincification. Zinc's melting point is at the low end of the temps necessary for annealing brass, it's boiling point is a little beyond the high end. Copper's MP is well above this so the risk in overheating is to the Zinc content and brass matrix. In an oxygen-bearing atmosphere Zinc will oxidize at room temperature over time. Oxidation accelerates at elevated temps.
There's a relatively simple test you can do to get an idea of the effect your annealing practices have on cases. Take three fired cases of the same type. Heat the neck of one for six or seven seconds in a propane torch. Heat another until it's bright, cherry red then keep it at that temp for a count of ten. Let both cases cool to room temperature.
Now take a pair of pliers & crush the necks of each case, starting with the overheated one. End up with the unannealed one. It's a crude experiment but worth your time if you'r just starting to deal with what it takes to anneal cartridge cases both to extend their useful life and to improve their response to resizing operations.
Forum Boss
Administrator
Larryh128 said:
NO NO NO NO!! An over-annealed neck gets soft and weak!
If you're over-annealing the neck to the point of dangerous softness you are almost surely going to cook the case below the shoulder. Even with a heat sink you can still potentially weaken the case. Remember that the entire case is a pressure vessel operating at up to 63,000 psi!
If you over-anneal ANY part of the case, THROW IT AWAY!! You can't restore the neck so it's not going to ever shoot properly anyway.
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