Shootin4fun
Well-Known Member
Which heat sensor do you use? Does it work to measure the brass temperature when it is still in the flame?
Salt Bath Annealing Doesn't Work! by AMP
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Hardshot
Well-Known Member
+1
In my book, all that really matters is measured ES and SD. I've been hand loading for decades, and as dumb as it might sound only learned of annealing in the last year.
My limited tests using the torch method (with the eez "machine") have made 3x fired cases of Lapua 6.5CM go from teens SD to single digit. (Magnetospeed V3) Several times now. New out of the box they were single digit.
But the torch method does require sacrificing some cases to get the right dwell time/temp. It is a bit subjective to say the least. There exists the issue of "to glow or not to glow".
My initial tests with 243 adn 270 are also promising but not conclusive due to small sample size. For some reason, the 6.5CM in both Lapua and Hdy were easier to get to a consistent temp over a consistent length of the case than the other 2.
Well, I have come to look at it as just another excuse to spend more time at my hobbies and profession...which seems to be running tests regardless if it's PHOTOGRAPHY, SHOOTING, or AUDIO/VIDEO ENGINEERING all in pursuit of some holy grail of perfection!
LoL, There are endless debates about 4K vs 8K film scanning and electronic image capture and 10 bit vs 12 bit vs 16bit color depth...or 98KHz vs 192Khz audio sample rates or the difference between speakers costing $3500 vs $6500 vs $50K / pair and I'll refer you to a couple of other forums.
Hardshot
Well-Known Member
That last post was a Brain fart on the buttons
Hardshot
Well-Known Member
I have been welding for my whole life and I have never seen the metal hotter at the finish end than the end we're the torch was cutting away the materials.
I have had my salt Annealing system for two weeks and by trial I have discovered that if I keep the salt so it goes half way up the shoulders it does the best looking work .
Each different case works some what differently , I think it's the thickness of case ,changes the way and time it takes , a 6 ppc or 6 Br and then a 30 -338 all need different timing .Just my 2 cents can't wait for the feed back from Ballistic Solutions.
I have had my salt Annealing system for two weeks and by trial I have discovered that if I keep the salt so it goes half way up the shoulders it does the best looking work .
Each different case works some what differently , I think it's the thickness of case ,changes the way and time it takes , a 6 ppc or 6 Br and then a 30 -338 all need different timing .Just my 2 cents can't wait for the feed back from Ballistic Solutions.
ntsqd
Well-Known Member
I'm going to guess that the 6PPC needs less time than the 6BR by a tiny bit, and both need less time than the .30-338. Brass is a decent thermal conductor. More brass to a case makes a better heat sink, so longer immersion time for the bigger cases would make sense.
cardon1122
Well-Known Member
Hardshot's observation that best results were with the salt surface at mid-shoulder level makes sense. Look at AMP's chart 3. They placed the salt level 5mm above the shoulder for 20 seconds and got inadequate annealing of the neck but over-annealing of the shoulder and distal body. Their ideal annealing curve has a hardness of 95-110 HV of the neck/shoulder area then a steep increase in hardness beyond. Notice that points 5-9 of the case in chart 3 are between 95-110 HV with steep increase in hardness beyond. Cut off the first 4 points and shift the curve over and you have a curve pretty close to their ideal curve. This suggests that having the neck closer to the surface with the surface level somewhere on the shoulder, annealing for 15-20 seconds might well create an annealing curve close to the ideal. It would be nice to test the theory and see if it's correct. If it is, you'd have a system doing a great job annealing your cases for about one fifteenth the cost of AMP's annealer!
Hardshot
Well-Known Member
Yes that was my experience. I have only had this for maybe three weeks so in needed to find what was to work for me with the guidelines that the manufacturer said. I have done about 300 plus shells of various calibers . I have not damaged anything that I am aware of . I used a few .243 junkers to test the waters sort of speak.This was much more friendly than my experience with the torch and drill .
I found I needed to adjust the liquid height for different shells ,this is easy with a desert spoon from the wife's kitchen.Just dump the liquid salt onto a piece of aluminum plate ( It's really hot so have everything set up to not burn yourself).When your done you just scrape of the cooled white salt and re use it.
I started out at the 550 temperature range with some 6.5 x .284 in Lapua and the same temperature for large .30 -338 in Nosler ( about 6 -7 seconds and they looked like the new ones come.)
The smaller cases 6 ppc ,6Br Norma at about 510 celsius for 5 seconds and 6 on the Br brass .
I just think it works because of what they look like and my seating pressure after Annealing seem to be much more consistent. I had up to 20 shots on the Ppc cases and they were seating with too much variation in seating pressure.So I either anneal them or replace them and that's why I bought this system. I also wanted to spend my money on bullets and powder not a very expensive Annealing machine.
As a foot note I don't believe anywhere in the instructions does it say to put your brass into the salt that far or for that long . I look forward to one of you guys that can do a independent test to share your results as when I first started to read this long post I thought perfect I just bought a lemon.At this time I have my own testing and I am happy .
Cheers to all the great people helping others and the newbies on this great form.
J E Custom
Well-Known Member
No. I don't get consistent readings in the flame. I use the Templac to get the inside temperature of the neck, and with that set I check the temp of the case mouth immediately a with the Laser as soon as it drops out before it is quenched to get a base line that I can monitor.
I run two or three to get the temp right with out quenching and then start quenching. Occasionally I will sample the cases buy catching one before it goes to quenching and just re run it.
Different brands have different times because of thickness and must be set up buy cartridge size and brand so when I set up I sort in batches by brands and cartridge. I also like to polish/tumble my cases before I anneal them because it helps in keeping the cases free of any possible contaminates and aids in evaluating the finished product for consistency.
J E CUSTOM
I have several problems with the AMP test. The reported results do not match my experience.
1) The oxidation on the outside of the salt bath samples does not match the the photos of the inside.
2) After salt bath annealing more than 500 .308 cases, I've never seen that level of oxidation. I tried again this evening by annealing at 500°C for 15 seconds and barely had any color change at all.
3) I find it hard to believe that the shoulder would be softer than the neck after salt bath annealing. The thin neck will heat faster than the shoulder ... which is also losing heat to the body. Even if the case was air cooled, the shoulder would cool faster than the neck ... conduction is more efficient than convection. The only way I can imagine a softer shoulder is that the case started with a softer shoulder and the neck didn't get hot enough, long enough, to soften.
I will be talking to the local test lab to see what it would cost to hardness test a couple of my own salt bath annealed cases.
1) The oxidation on the outside of the salt bath samples does not match the the photos of the inside.
2) After salt bath annealing more than 500 .308 cases, I've never seen that level of oxidation. I tried again this evening by annealing at 500°C for 15 seconds and barely had any color change at all.
3) I find it hard to believe that the shoulder would be softer than the neck after salt bath annealing. The thin neck will heat faster than the shoulder ... which is also losing heat to the body. Even if the case was air cooled, the shoulder would cool faster than the neck ... conduction is more efficient than convection. The only way I can imagine a softer shoulder is that the case started with a softer shoulder and the neck didn't get hot enough, long enough, to soften.
I will be talking to the local test lab to see what it would cost to hardness test a couple of my own salt bath annealed cases.
JimmyCP
Well-Known Member
Brass is an alloy harden buy slow cool and working. I use a high temp salt good to 1650 F. Hard to say 500c isn't hot enough which is a guage both ways depending on the brass.. I think everyone says 500c to give a general idea when the dont know what color to look for when heating.
I have also heard and read guys stating you'll burn the tin out of the brass if the case is heated to high. Most case brass has very little if not any tin in it.
Brass is heated to a dull red, slowly air cooled and worked to harden. It's a plum to black color almost turning red before a quench to anneal.
Been annealing brass and other alloys for over 20 years. Any metalergy book and most blacksmith info will tell you the same as I have stated.
I have no problem with the salt bath annealing tooling brass rod before I work it, which is harder on the scale than case brass.
Problem with using on constant temp is the brass could be thicker or harder which would require more soak time to achieve the desired temperature or less soak time for softer thinner brass.
Same goes if you were to use a flame or torch where watching the color is crucial and time can not be dependable.
MN-50 Shooter
New Member
While I know my results are only anecdotal, I have proven to myself, that using the Salt Bath method of annealing, gave better results than using the torch method.
I shoot 1000 yd 50 BMG Matches (FCSA) and after changing to the Salt Bath method (exclusively) last year, my results greatly improved. I also have seen a marked improvement in my chronograph testing, in regards to SD & ES.
This year will be my second year using the SB method of annealing, using the same brass, that I anneal after each firing. I'm planning to compare my results from last year to see if last year was just a one off, or there is consistency from year to year. I'm hoping that I will see similar results this year.
Just a note: My necks are turned to .0195" thickness and I anneal my brass at 550°C for 10 seconds. I'm annealing Israeli 1990 brass which I have found to suit my needs quite well.
I shoot 1000 yd 50 BMG Matches (FCSA) and after changing to the Salt Bath method (exclusively) last year, my results greatly improved. I also have seen a marked improvement in my chronograph testing, in regards to SD & ES.
This year will be my second year using the SB method of annealing, using the same brass, that I anneal after each firing. I'm planning to compare my results from last year to see if last year was just a one off, or there is consistency from year to year. I'm hoping that I will see similar results this year.
Just a note: My necks are turned to .0195" thickness and I anneal my brass at 550°C for 10 seconds. I'm annealing Israeli 1990 brass which I have found to suit my needs quite well.
J E Custom
Well-Known Member
[QUOTE="4SFED,
I will be talking to the local test lab to see what it would cost to hardness test a couple of my own salt bath annealed cases.[/QUOTE]
Ask them about the Brinell test. There is even a portable Brinell tester that should be cheaper for them to perform.
https://www.worldoftest.com/portable-hardness-testers-handheld-hardness-testers
J E CUSTOM
I will be talking to the local test lab to see what it would cost to hardness test a couple of my own salt bath annealed cases.[/QUOTE]
Ask them about the Brinell test. There is even a portable Brinell tester that should be cheaper for them to perform.
https://www.worldoftest.com/portable-hardness-testers-handheld-hardness-testers
J E CUSTOM
A few observations on material behavior, quenching, Tempilaq, and objectives. Let's take the last one first: there appear to be two different objectives among the commenters here. One is absolute case-case uniformity for consistency of neck tension in a benchrest shooting application; the other is increasing case life by eliminating work-hardened split necks in a reloading application. The first, it seems to me, is a competitive undertaking where results are the object, and cost is a lesser consideration; the second is a reloading cost (extending case life) undertaking, where cost is almost paramount (assuming the technique works). I wouldn't think the twain would meet.
On material behavior: my understanding is that cartridge brass does NOT behave like ferrous metals, and so rules applicable to the latter really have no place in the discussion. Nor aluminum, which is yet a different animal. My understanding is that it is more like chalcogenide materials, about which my understanding is as follows - this from analysis of the behavior of same in phase change, laser-based rewriting applications in optical disk. When such a material is heated, the molecular structure becomes disordered; you can think of melting as an extreme example, where all crystalline structure is disaggregated.
Upon cooling, one of two things will happen: if cooled rapidly, crystals will have no time to form; the material is then said to be amorphous. If cooled slowly, the material has time to order itself into a crystalline structure. The two phases of the material have different optical, reflective, directional (depending on the class of crystal) and hardness properties. The objective of annealing is to take brass, which has been work hardened into a more ordered but stressed state, and return it to a more nearly amorphous, stress-relieved microcrystalline phase, so that word-induced large grain boundaries do not lead to internal discontinuities in the material, that initiate material separations - leading to splits of the case mouth, with potential catastrophic results, and also rendering the brass useless for reloading. Amorphous or small, microcrystalline, structure more evenly distributes stresses throughout the material, and eliminates large-scale grain boundaries that cause this type of failure.
Quenching from the temperature at which the material has become disordered enough that large-scale boundaries are eliminated - and microcrystalline structure prevails - prevents further crystal formation associated with long cooling times above the critical point. But in the case of brass, there is a more practical issue: that of conducted heat moving down the cartridge body to an area in which you do not want softness. So quenching in brass is not an aspect of the materials treatment process so much as it is a localization of heating effects technique. That is, if you want to treat one area and one area only, heat it and then - since metal conducts heat readily - cool it before the heating spreads. That's one of the reasons for heating necks of cases standing in a water bath - not so much the quenching, as the use of the water to stop the propagation of heat down the cartridge body from either flame contact or conduction.
Finally, Tempilaq and visual assessment of temperature. If the brass is heated to the point where you can see it glowing, it has been overheated. That is readily apparent by use of a thermal indicator paint like Tempilaq, which is applied to the case neck before heating; it changes appearance when it reaches a predetermined temperature (it comes in a variety of temperature transition points). You will not be able to see a case glow before the Tempilaq reaches the indicator point. In addition, the surrounding light intensity and light color in the room in which you are annealing will change your threshold of perception of the glow, leading to inconsistent results. This is exactly the problem that led to improperly heat-treated receivers of Springfield rifles in WWI, when reliance on visual indication of steel temperature, which in unlighted factories had been the standard for experienced metallurgists, was improperly applied by less-skilled steelworkers in lighted factories, with much-weakened, overheated receivers resulting. So: use Tempilaq until you have standardized your procedures, and check back periodically with it for quality control.
I hope this helps to shine some light on the processes involved, and stimulates additional descriptive refinements of what's happening, by others who are materials specialists.
On material behavior: my understanding is that cartridge brass does NOT behave like ferrous metals, and so rules applicable to the latter really have no place in the discussion. Nor aluminum, which is yet a different animal. My understanding is that it is more like chalcogenide materials, about which my understanding is as follows - this from analysis of the behavior of same in phase change, laser-based rewriting applications in optical disk. When such a material is heated, the molecular structure becomes disordered; you can think of melting as an extreme example, where all crystalline structure is disaggregated.
Upon cooling, one of two things will happen: if cooled rapidly, crystals will have no time to form; the material is then said to be amorphous. If cooled slowly, the material has time to order itself into a crystalline structure. The two phases of the material have different optical, reflective, directional (depending on the class of crystal) and hardness properties. The objective of annealing is to take brass, which has been work hardened into a more ordered but stressed state, and return it to a more nearly amorphous, stress-relieved microcrystalline phase, so that word-induced large grain boundaries do not lead to internal discontinuities in the material, that initiate material separations - leading to splits of the case mouth, with potential catastrophic results, and also rendering the brass useless for reloading. Amorphous or small, microcrystalline, structure more evenly distributes stresses throughout the material, and eliminates large-scale grain boundaries that cause this type of failure.
Quenching from the temperature at which the material has become disordered enough that large-scale boundaries are eliminated - and microcrystalline structure prevails - prevents further crystal formation associated with long cooling times above the critical point. But in the case of brass, there is a more practical issue: that of conducted heat moving down the cartridge body to an area in which you do not want softness. So quenching in brass is not an aspect of the materials treatment process so much as it is a localization of heating effects technique. That is, if you want to treat one area and one area only, heat it and then - since metal conducts heat readily - cool it before the heating spreads. That's one of the reasons for heating necks of cases standing in a water bath - not so much the quenching, as the use of the water to stop the propagation of heat down the cartridge body from either flame contact or conduction.
Finally, Tempilaq and visual assessment of temperature. If the brass is heated to the point where you can see it glowing, it has been overheated. That is readily apparent by use of a thermal indicator paint like Tempilaq, which is applied to the case neck before heating; it changes appearance when it reaches a predetermined temperature (it comes in a variety of temperature transition points). You will not be able to see a case glow before the Tempilaq reaches the indicator point. In addition, the surrounding light intensity and light color in the room in which you are annealing will change your threshold of perception of the glow, leading to inconsistent results. This is exactly the problem that led to improperly heat-treated receivers of Springfield rifles in WWI, when reliance on visual indication of steel temperature, which in unlighted factories had been the standard for experienced metallurgists, was improperly applied by less-skilled steelworkers in lighted factories, with much-weakened, overheated receivers resulting. So: use Tempilaq until you have standardized your procedures, and check back periodically with it for quality control.
I hope this helps to shine some light on the processes involved, and stimulates additional descriptive refinements of what's happening, by others who are materials specialists.
Because articles regarding brass annealing consistently state that quenching does not make any difference at all.
Other metals yes, brass no.
So, I don't quench.
Several other posts here mentioning the same.
