Annealing - Fast and Hot OR Slow and Warm

[noload]

Here http://www.nlrc.org/index_htm_files/Ryan Stevenson - Dissertation.pdf is a very interesting scientific study about cartridge brass. It's long and most people will not take the time to read it (even though serious reloaders should).

They used the hand held Drill-And-Torch method of annealing because that is what many reloaders use. The experimenters calibrated their procedure time using Tempilaq and then attempted to duplicate the same procedure for each case. This proved not to be a good approach. They concluded that: "The annealing process is not able to apply consistent amounts of heat to each cartridge that is annealed. ............cartridge brass (30% Zn) is usually well within the face centered cubic α phase of brass. Thus, the rate of cooling after the annealing process should not greatly affect the microstructure of the material as long as the cooling process can be kept consistent for all of the annealed cartridges. The variability in annealing results is therefore most likely caused by an inability to accurately control the temperature and time of the heat treatment process........"

They determined that (when examined under a microscope) the post-annealing grain structure of the sectioned cartridge necks varied from one side of the neck to the other. They went on to say: "The microstructure variability after annealing will have consequences for shooting accuracy as one round may react differently to another. Large variations in microstructure, with circumferential position, in a single cartridge may affect the way in which a bullet leaves the cartridge during firing and thus further affect shooting accuracy. ............................... the results suggest that an improvement in the neck annealing process could greatly increase the ability to control the material properties of the cartridge cases. A more controllable annealing process would decrease the variability of the annealing results achieved and could help to maintain accuracy when shooting."

They determined that it might be better not to anneal at all rather than use a less-than-optimum procedure, such as the drill-torch method.

After further discussion about neck hardness in cartridges fired and reloaded several times without annealing, the conclusion was: "This suggests that if annealing is to be carried out it should be done on a regular basis."
They made some careful measurements of hardness at a number of points along the length of the case and plotted that information for factory brass, fired brass, and fired brass, which was subsequently annealed. In short, they proved what most of already believe; i.e. necks get harder the more they are fired and reloaded. Necks can be returned to near-factory condition after DIY annealing. Down around the base, hardness remain pretty much the same and proper annealing does not dangerously soften the base. Resizing causes thinning of the cartridge just above the base. Improper neck turning can cause a notch and/or burr at the top of the shoulder and should be avoided. No real surprises here, but it is nice to have scientific confirmation.
The experiments relating to actual seating force and extraction force was flawed and the failed to produce useful information and that is a real shame in my opinion.

After reading the entire study, I confirmed my belief that a good annealing machine, such as my DIY "Skip Design" unit, carefully calibrated using Tempilaq, is better than using a hand held torch and "counting" the annealing time. I have confidence that my annealing machine is not damaging my cartridge bases and that the condition of my brass, which I anneal each time, is returned to near-factory condition, which is helping to make my neck tension more consistent.

I liked the scientific study about cartridge brass. It was a lot of work and the results did not surprise me.

 

[dmoran]

Mozella -
Thanks for sharing the link......... exceptional information and a great study.
Donovan

 

[6MMsteve]

I will not drink the Kool Aid only a sip

 

[SWRichmond]

I get the idea you're making posts here mainly be argumentative but I wonder if you're also missing the larger point. The dissertation you so dismissively put between quotation marks is indeed just that; a dissertation. Unless it is I who is missing the point and the paper is a complete hoax ginned up by some 9 year old kid in his Mom's basement. Somehow I doubt that, but I could be wrong.

You may not like it and you may disagree with the entire paper and you may even think that it doesn't deserve a passing grade; however, that doesn't make somehow less than a genuine dissertation. Neither is the information there worthless just because you fault them for not testing the results of the annealed cases by test firing loaded cartridges. They also didn't give details on how to make a Shoo-Fly pie either. Do you fault them there as well?

The idea was simply to take a look at what happens to cartridge brass when you anneal it. I think they did a decent job doing that. True, Mr. Stevenson didn't go the rifle range, but that wasn't part of his plan even though you seem to think he somehow short changed you. After all, the title wasn't "The Grand Unified Theory".

Well, for starters, the paper uses the F Class shooter almost as bona-fides, to lend credibility to the results. If one wishes to use a sport (shooting), and a champion shooter as examples in his paper, why would one omit testing the only results which actually matter to the sport and the shooter, that is, the results on the target? The paper discusses metallurgy, and makes allegations about the impact of that metallugical consistency (neck tension), but does absolutely nothing to prove the allegations. All of which I stated in my post.

In fact there's quite a bit of information to be gleaned from the "dissertation", as you put it. The fact that cases annealed using the drill/torch method were inconsistently annealed is only one useful observation.

But that "fact" does not necessarily correlate to any actual effect on the target, and any assertion that it does correlate is at least erroneous, if not disingenuous.

Furthermore, the anecdotal account presented in this thread by a fellow forum member who noticed increased precision after he began annealing doesn't make it non-factual just because he didn't have support from NASA

Well, no not NASA, but this was allegedly an academic thesis, yes?

Additionally, some of us who shoot have been formally educated in the science of metallurgy and many of us anneal in a reasonably precise way. We we have also carefully measured and recorded the before-and-after effects of that annealing process as far as how it effects the precision of our rifles.

I wonder if being too quick to dismiss findings which are not full and complete scientific studies covering each and every aspect of the shooting sport isn't being a bit short sighted. Most of us are here to learn something.

Show me the results of those measurements, and tell me how the other variables were controlled. Or not. Were the data collected in a blind or double-blind study? Did the shooter know which ammo was being used? Does "human nature" suggest that knowledge might have influenced results?

I am also here to learn, but I want to learn facts, and not assertions or allegations. I am not saying that annealing does not matter, but anyone who wants to lend the aura of science to statements to that affect had better be genuinely scientific about it. And I haven't seen any actual science yet that would correlate annealing to precision on a target. And if that weren't enough, we have people here telling us we need to anneal "correctly", and we have people telling us what "correctly" means, all while no one has, as far as I know or can find, done any actual scientific study to show what "correct" annealing is with regards to accuracy of fired rifle cartridges. Does it "make sense" that consistent neck tension would result in better consistency in velocity, and thus accuracy at distance? Yes, it makes sense. But that is most emphatically not science.

I know what science is, and what I've seen so far ain't it. Maybe that's what I mind so much. If A=B and C=D, that does not mean that A=D.

On the subject of reloading: Let's be clear: I want to do the things which matter, and do them correctly. I don't want to waste time, effort and money doing things which do not matter nor doing them incorrectly.

Enjoy spending your money, and I hope you feel good about it, because that's what money is for.

 

[dkhunt14]

I know what science is, and what I've seen so far ain't it. Maybe that's what I mind so much. If A=B and C=D, that does not mean that A=D.

Well you might know science and I know it was a very long time since I was in school, but when I went to school they called this above statement Algebra. Matt

 

[Dos XX]

SW Richmond,

I don't see where you mentioned what testing you did to test what difference annealing made for you on target? Can you provide some information about that testing? I am not that interested in something you read about.

What discipline(s) do you shoot? Give us an idea of your experience / competence level, high master NRA, accomplished Bench Rest shooter, XTC, etc?

 

[skidmarks]

I am interested what and where those of you that bought regulators and pressure gauges for your annealing machines. Thanks Brian.

 

[SWRichmond]

SW Richmond,

I don't see where you mentioned what testing you did to test what difference annealing made for you on target? Can you provide some information about that testing? I am not that interested in something you read about.

What discipline(s) do you shoot? Give us an idea of your experience / competence level, high master NRA, accomplished Bench Rest shooter, XTC, etc?

My shooting classifications are irrelevant to the science. Suffice it to say if you examined posted scores for long range matches over the recent 3-5 years you would see my name repeatedly.

I am in the middle of rethinking a lot of what I think I "know" about shooting and my rifle / ammo system, and so I am questioning orthodoxies like "proper annealing". As far as I can tell, no one has done a statistically reliable study to determine what "proper" actually means with respect to rifle accuracy. There is a lot of innuendo and conjecture.

I have been greatly guilty of this myself, claiming great results at long range after bullet pointing, posting three shot groups of load development and declaring victory, etc. None of the testing I have done has been "blind", which means I know which ammo I am shooting, and thus, seeking confirmation of my effort, I cannot say that I can trust the results of my "testing". I "think" that meplat uniforming and pointing improves scores, and it "makes sense" that doing those things "should" improve long range results, but for me to say my scores went up after I did those things proves nothing at all. I am improving constantly as a shooter, conditions vary greatly from match to match, the rifle barrel is wearing all though this process...there is nothing scientific about it, at all, and any attempt to make it sound scientific is misleading.

Another example is: Too much of what I "know" is based on three shot groups, which are not statistically significant. Any information gleaned from three shot groups is unreliable. Probabilities and statistics being what they are, I believe that an actual predicted group size is more than twice the size of any three shot group. This also means the "center" of any three shot group is unreliable, perhaps extremely so, and this means many of the methods often cited for load development are in truth not statistically reliable. Everyone loves them, but they are not real. I am going back to shooting ten shot groups.

So I am also closely and critically examining the claims of annealing, and I find that I have been unable to find actual science which conclusively and directly relates any annealing process to long range accuracy. If someone has a link to an actual scientific study, preferably a blind one, where annealing was compared to non-annealing and the results were followed through all the way to long range group size, I would be most appreciative. Hopefully, that study would include information about exactly what annealing process was used (temperature, time at temperature, case neck thickness, quench if any, case chemistry, case use, etc). Such would be a very expensive study to do. I sincerely doubt it has been done.

 

[dkhunt14]

I don't need science to tell me a certain pie or cake tastes better then another one. I also don't need science to tell me what looks better on paper. Matt

 

[Webster]

I don't need science to tell me a certain pie or cake tastes better then another one. I also don't need science to tell me what looks better on paper. Matt

Can you tell how well a case is annealed by tasting it. You determine how much brass is annealed by determining the hardness. You determine if it makes a difference by looking at the targets.

 

[dkhunt14]

Can you tell how well a case is annealed by tasting it. You determine how much brass is annealed by determining the hardness. You determine if it makes a difference by looking at the targets.

No, just saying sometimes science can't explain results. Targets tell me if it works. I don't shoot them close either, at 1000 where results show up. My targets tell me it works. Matt

 

[R.Morehouse]

So from reading the ....Conclusions & Recommendations....page of the R.Stevenson study i guess induction with a precise timer and anneal every time would most likely be the "best" way to get it done.. www.fluxeon.com I have one of these compact little units that works just fine....Has no flame and takes up very little space. Mine has worked for about 1000 rounds so far with out issue. I am a very low volume shooter so I only do around 100 at a time max. Overheating has not been an issue so far...

 

[Dos XX]

My shooting classifications are irrelevant to the science. Suffice it to say if you examined posted scores for long range matches over the recent 3-5 years you would see my name repeatedly.

I am in the middle of rethinking a lot of what I think I "know" about shooting and my rifle / ammo system, and so I am questioning orthodoxies like "proper annealing". As far as I can tell, no one has done a statistically reliable study to determine what "proper" actually means with respect to rifle accuracy. There is a lot of innuendo and conjecture.

I have been greatly guilty of this myself, claiming great results at long range after bullet pointing, posting three shot groups of load development and declaring victory, etc. None of the testing I have done has been "blind", which means I know which ammo I am shooting, and thus, seeking confirmation of my effort, I cannot say that I can trust the results of my "testing". I "think" that meplat uniforming and pointing improves scores, and it "makes sense" that doing those things "should" improve long range results, but for me to say my scores went up after I did those things proves nothing at all. I am improving constantly as a shooter, conditions vary greatly from match to match, the rifle barrel is wearing all though this process...there is nothing scientific about it, at all, and any attempt to make it sound scientific is misleading.

Another example is: Too much of what I "know" is based on three shot groups, which are not statistically significant. Any information gleaned from three shot groups is unreliable. Probabilities and statistics being what they are, I believe that an actual predicted group size is more than twice the size of any three shot group. This also means the "center" of any three shot group is unreliable, perhaps extremely so, and this means many of the methods often cited for load development are in truth not statistically reliable. Everyone loves them, but they are not real. I am going back to shooting ten shot groups.

So I am also closely and critically examining the claims of annealing, and I find that I have been unable to find actual science which conclusively and directly relates any annealing process to long range accuracy. If someone has a link to an actual scientific study, preferably a blind one, where annealing was compared to non-annealing and the results were followed through all the way to long range group size, I would be most appreciative. Hopefully, that study would include information about exactly what annealing process was used (temperature, time at temperature, case neck thickness, quench if any, case chemistry, case use, etc). Such would be a very expensive study to do. I sincerely doubt it has been done.

I agree about the 3 or 5 shot group and declaring it good. I have been guilty of this myself. I mostly use 5 shot groups for initial load development and follow up with 10 shot groups. I got lazy recently because it was cold and shot 3 shot groups and a follow up 5 shot group a week later convinced me I didn't need to try a 10 shot group with that load.

It is also easy to change something or add a step to your reloading process and shoot a great score at a match and then declare that change or step necessary. I have done it. It sometimes is easier to add the additional step to your reloading process than it is to actually thoroughly test it, especially if your test range is some distance from your house. I have tested changes in matches by shooting different variations in different relays, but then the conditions change and the results may not be conclusive. Even if you had a tunnel, the load you came up with in the tunnel might not shoot as good in the wind as a load you developed in the wind. It isn't easy knowing what makes a difference. However, if you do something and your scores go up, tough to go back.

I personally have tested annealing enough that I am convinced for my own shooting, it helps. I find that shoulder bumping is more consistent and bullet seating is more consistent on annealed brass. My groups and scores also improved. Yes, you can argue that my score improvement is confirmation bias if you want, but I don't buy it. It would be tough to argue the resizing consistency is confirmation bias, however. "Proper annealing" to me is annealing that improves the consistency of my resizing, bullet seating, and groups/scores. Whether I "over annealed" or "under annealed" or "improperly annealed" by some criteria doesn't matter as long as they are safe and I see the improvements mentioned.

I asked about what discipline you shoot as I think it is possible that annealing can have a greater affect on certain cartridges, or maybe more precisely different neck clearances and sizing practices. A .308 running .005 or .006 neck clearance that is shoulder bumped .002 would seem to be to work harden more quickly than a cartridge with .001 neck clearance that is only neck sized, wouldn't it? Also, some disciplines require more pure accuracy than others.

I asked about your experience as your opinion about annealing runs contrary to what some very accomplished shooters, some on this very thread, believe about annealing, and I don't include myself in the description," accomplished shooter". It is tough to weigh an opinion of someone that you don't know anything about versus that of someone that you are aware of their accomplishments. If you further your testing, I would be interested in the results, but would like to know what cartridge, neck clearance, sizing routine, discipline, etc. your testing applies to.

 

[Webster]

I liked the scientific study about cartridge brass. It was a lot of work and the results did not surprise me.

My opinion after rereading Ray Stevens Study:

He states that the hardness is inconsistent based on graph p. 43 table 1. I agree, but it’s important to recognize the data does not represent annealing a group of like case necks and looking at the neck hardness variation around an individual case neck or between like cases annealed the same way. The cases were processed in at least five different ways and compared on the graph. The bottom line is a consistent method and shoot them at a target. You probably won’t see any difference in targets at 100-300 yards? Torch annealing is fine for my needs, gh hunting and casual 100 yrd. BR. I don't see any difference at 100 yds. so I am OK. Seldom shoot beyond 300 yds. I anneal for case life. My 6BR shoots small groups so I don't worry about it. I just need to find more of the nearly extinct GH in Ohio.

Good luck everyone the PowerBall may reach 2 billion by Wednesday. You can buy an annealer for everyone you know.

I am sure case necks are not x-rayed for internal cracks at the factory. Iron oxides are a common contaminate in copper alloys. A microscopic piece of iron oxide in the neck would increase the probability of cracking at some undetermined time.

,

CHARACTERISATION STUDY OF BRASS CARTRIDGES FOR HIGH END COMPETITION TARGET SHOOTING

RYAN STEVENSON


P. 43 Table 1 Hardness at difference stages.


P. 65

Throughout the investigation it was shown that the neck annealing process produced inconsistent end results. A few solutions could be applied to combat this. The simplest, would be to drop the neck annealing procedure altogether. This would reduce the lifespan of the cartridge but would ensure that all cartridges would exhibit relatively consistent material properties throughout their lifespan. There would obviously be a resultant downside in terms of cost.

 

[savagedasher]

One of the things in that study that really stuck out to me, and I think I read it right (twice). They said the brass did not harden from working it, but instead it hardened from shooting it. I was always thinking it worked the exact opposite of that. Did I miss something, it wouldn't be the first time?

Tom

Brass gets stress hardened. Larry

 

[Webster]

One of the things in that study that really stuck out to me, and I think I read it right (twice). They said the brass did not harden from working it, but instead it hardened from shooting it. I was always thinking it worked the exact opposite of that. Did I miss something, it wouldn't be the first time?

Tom

Brass work hardens from sizing and shooting. Both stretch the brass. Without rereading I think he thought shooting cold worked it more. I am tired of talking about annealing but I think I can add a few things that are probably info and don't help any. The strain rate should affect how much the brass is cold worked/strained. Sizing stretches the brass slowly, shooting stretches it several thousands of an inch in well under 1/1000 of a second. It's called strain rate sensitivity.