Annealing Machines in Late 2018

[dcali]

I disagree. Unless you use very light neck tension, you yield the neck when you seat a bullet.

 

[SGK]

Lapua anneals because the forming process requires it - there is a lot of working of the brass and it splits if you don’t anneal at appropriate times. As for why the machines are sold? Because people will buy them.

As opposed to the working as a result of repetitive expansion and contraction from firing and resizing... My reference was to the large scale commercial machines - such as the one in the link provided - not those oriented to 'individual' use. So they are needed to offset the work hardening associated with hammering the brass to cartridge shape from a flat disc or small cup-like input material. I'm all for learning more about how that work hardening differs from the forces of firing and resizing.

Building an induction annealer needn't cost much. A base level implementation can be done for well less than $400. Cheap and fun to build and use.

 

[Laurie]

Lapua anneals because the forming process requires it - there is a lot of working of the brass and it splits if you don’t anneal at appropriate times. As for why the machines are sold? Because people will buy them.

One of these little known facts these days is that ALL .303 British and Commonwealth military ammo loaded with Cordite used unannealed brass. Since most 303 from the MkII to the final Mk VII, a span of over 60 years, used Cordite that amounts to many hundreds of millions of cartridges - if not billions. (The exceptions are the Mk 7z loaded for machineguns and that loaded by US companies during WW2 and supplied under Lend-Lease arrangements all of which used conventional extruded / chopped or for WW2 Winchester loaded ammo ball powders.)

The reason for this was that the charge was in the form of 2-inch long bundles of the strands (ie 'cords' hence the propellant's name) and that they couldn't be inserted into a fully formed case with shoulder and neck in situ. So the cases were formed at the rear end, drawn to the appropriate length and taper, primed, charged and only then was the shoulder and neck swaged on. As the case had the charge installed it couldn't now be annealed for obvious reasons.

The various operations in drawing and forming the case make the brass very hard, but brittle, hence the reason for neck / shoulder annealing as damoncali rightly says. IIRC Lapua uses three separate annealing steps in its brass on the upper case-walls as well as the final neck/shoulder. It produces a hardness gradient not just at the very front end but lower down too from the very hard never annealed case-head / web and lower walls to the relatively very soft neck. Another reason for the intermediate annealing is no doubt to reduce wastage from splitting in the multiple draw / swaging processes to get from the 'coin' (flat disk) to the final shape.

Returning to the 303 Cordite ammunition series, shoulder and neck splits were very common in unfired stored ammunition even though it was all in airtight sealed metal boxes. So people who bought say 20 year old surplus 303 would sometimes find that most of the rounds were unusable. This was purely from the neck tension / crimp on the bullets - the unannealed brass would only take it so long before the necks cracked. I remember a friend buying a vast quantity of South African 303 Mk VII in the 1980s and finding around three-quarters had neck splits on opening the cans. (Those that hadn't already split did so on firing unsurprisingly.) They were in perfect condition otherwise, bright and shiny as if they had only just left the factory.

Hence why manufacturers anneal brass in case-forming. But that is a quite different reason / issue from a handloader re-annealing between firings/loadings.

 

[dcali]

As opposed to the working as a result of repetitive expansion and contraction from firing and resizing... My reference was to the large scale commercial machines - such as the one in the link provided - not those oriented to 'individual' use. So they are needed to offset the work hardening associated with hammering the brass to cartridge shape from a flat input material. I'm all for learning more about how that work hardening differs from the forces of firing and resizing.

Building an induction annealer needn't cost much. A base level implementation can be done for well less than $400. Cheap and fun to build and use.

The main difference is in magnitude. The working that happens when firing or sizing is minor compared to the manufacturing process. Reloaders first got into annealing to help make wildcats for similar reasons. It’s only relatively recently that shooters have started to look to annealing as an aid to accuracy.

 

[rwj]

I'm all for learning more about how that work hardening differs from the forces of firing and resizing.

They differ in that the amount of cold work/deformation is order of magnitudes higher when forming the case (https://www.petersoncartridge.com/our-process/drawing-brass) relative to the small amount caused by fire forming in the chamber.

 

[JimSC]

precision shooting is like any competitive sport people are always looking for the magic tool they can buy to take them to the next level. It is that way in any sport. My neighbor has at least six sets of golf clubs, dozens of putters, and every swing trainer invented. He shoots mid 90's. When I was into bodybuilding people were destroying their auto immune systems to get a extra inch on the biceps. I am currently adopting the Jerry Mucilek approach. A couple of days a week I am the first one to the range and last to leave. I don't believe in magic pills anymore, when you get to a point with your equipment and ammo making the only improvement will be gained through practice. My goal is a minimum of 500 rounds a month between centerfire long range and rimfire practice

 

[SGK]

They differ in that the amount of cold work/deformation is order of magnitudes higher when forming the case (https://www.petersoncartridge.com/our-process/drawing-brass) relative to the small amount caused by fire forming in the chamber.

Of course. And why they anneal after each major draw/forming step. They anneal before and after the shoulder/neck formation, for example. How many firings/FL resizings equates to the material stress of that last shaping? I don't think any of us know. Is it materially different in nature (as well as magnitude)? JimSC appears to say 'yes'.

I would posit that the majority of people anneal for brass longevity rather than with an expectation of increased accuracy.

I agree with practice, practice - and don't do enough - but we do like to tinker when we can't be at the range.

 

[dcali]

It’s all the same. The more you work the brass the stronger and less ductile it will get until it fractures.

 

[oldduc]

The main difference is in magnitude. The working that happens when firing or sizing is minor compared to the manufacturing process. Reloaders first got into annealing to help make wildcats for similar reasons. It’s only relatively recently that shooters have started to look to annealing as an aid to accuracy.

My father was a “wildcatter” back in the 1950s and he routinely torch annealed cases when forming cases.

 

[JimSC]

Ok I am retired and have way too much time on my hands so I just spent the majority of a rainy Sunday morning reading obscure research papers on the elasticity of metals and heat treatment. There are a lot of conflicting opinions out there as evidenced by this link

https://www.researchgate.net/post/Will_the_Youngs_Modulus_E_value_change_with_heat_treatment

But the answer that made the most sense was this one.

Clint Steele
Swinburne University of Technology
There is a lot of guess work in these comments. As part of my PhD I investigated material properties with respect to randomness.
Plastic properties of metals, which are heavily influenced by dislocations, are significantly influenced by heat treatment. These processes change the structure, and the dislocations.
Elastic properties on the other hand are affected by the interactions between the subatomic particles. Heat treatment does not change the atoms themselves - only the arrangement.
Never confuse the two. Many do, and it causes issues like this.
If you take a look at the list of material properties for metals, then you will see that the plastic properties (yield and UTS) change a lot from material to material, but the Young's Modulus changes relatively little. This shows how the plastic properties can be easily influenced by heat treatment, but the elastic properties are not.

underlining my me. When dealing with a bullet inserted into the neck of a case before and during first part of it being fired we are into the first part of the curve, the elastic portion. As the neck expands the neck farther from gas pressure in a normal (not tight necked) chamber the metal expands past the elastic portion of the curve into the plastic region therefore neck tension on case bullet will be constant regardless of the hardness until the neck diameter passes from the elastic region to the plastic.

Apologies for beating the horse into strawberry jelly but this subject has fascinated me for two years now and I have had many many changes in my opinion during that time and I am one of those odd birds who loves to read technical papers. I found other research including Litz's limited testing that backs this up. Until I see some testing by a reputable lab or individual that contradicts this I will no longer be annealing my brass

 

[Jdne5b]

I dont know the science, and probably dont care. But after firing and loading some Lapua 223 brass 5 times, neck tension and bullet seating pressure after sizing was 0. I could seat and pull a bullet by hand. Groups had gone to crap, and I was chasing my tail. After annealing the brass, seating pressure was back around 30lbs and groups were back where they should be. Good enough for me to keep annealing every firing or every other if Im short on time.

 

[JimSC]

I dont know the science, and probably dont care. But after firing and loading some Lapua 223 brass 5 times, neck tension and bullet seating pressure after sizing was 0. I could seat and pull a bullet by hand. Groups had gone to crap, and I was chasing my tail. After annealing the brass, seating pressure was back around 30lbs and groups were back where they should be. Good enough for me to keep annealing every firing or every other if Im short on time.

It wasn't the annealing or lack thereof that gave you problems, otherwise back in the 70's 80's and 90's and even into the early years of this century reloader's would have to buy new brass every five loadings.

Annealing cases at home is a relatively recent "fad" as I keep pointing out. Precision shooting and reloading for precision shooting predate it by decades. I read that somewhere in the late 90's and early 2000's some reloaders used a candle to heat the necks which would have never have gotten the brass anywhere near annealing temps

But what the heck I have a beat up old ballcap that I wear every match and I am convinced that without that cap I would have more 8's than 10's on the target, if it gives you a warm and fuzzy then do it I say

 

[jlow]

I've used a BenchSource for many years and have used it to anneal many thousands of brass. Then the AMP came out but in all the discussion I have had I have never heard any evidence that it is better than a flame-based annealer.

I can understand those who are afraid of using an open flame, but other than that, nothing makes me think it is better.

I personally think the AMP is a very good annealer but considering that a perfect anneal means a tailored anneal for each piece of brass which it cannot do. Brass are all different because each have slight differences in brass thickness in the neck and in the body. This of course is why cases have different weight and why we turn necks even with Lapua.

Now one can neck turn to take care of the thickness variance in the neck, but you cannot turn to body. When you have more brass in the body, the case as a whole absorb more of energy which means you have to put in more energy to get the same degree of anneal.

This is NOT conjecture as anyone who has annealed brass of the same caliber but from different sources with different neck thickness will tell you cases with thicker neck (which means thicker body), take longer anneal time to get the same anneal.

So I don't see how an annealer even if it puts out exactly the same amount of annealing energy each time can give the same degree of anneal for every single piece of brass. To me, that's just impossible.

I am perfectly willing to change my mind if someone can explain how the AMP can overcome what I just explained.

 

[dcali]

I've used a BenchSource for many years and have used it to anneal many thousands of brass. Then the AMP came out but in all the discussion I have had I have never heard any evidence that it is better than a flame-based annealer.

I can understand those who are afraid of using an open flame, but other than that, nothing makes me think it is better.

I personally think the AMP is a very good annealer but considering that a perfect anneal means a tailored anneal for each piece of brass which it cannot do. Brass are all different because each have slight differences in brass thickness in the neck and in the body. This of course is why cases have different weight and why we turn necks even with Lapua.

Now one can neck turn to take care of the thickness variance in the neck, but you cannot turn to body. When you have more brass in the body, the case as a whole absorb more of energy which means you have to put in more energy to get the same degree of anneal.

This is NOT conjecture as anyone who has annealed brass of the same caliber but from different sources with different neck thickness will tell you cases with thicker neck (which means thicker body), take longer anneal time to get the same anneal.

So I don't see how an annealer even if it puts out exactly the same amount of annealing energy each time can give the same degree of anneal for every single piece of brass. To me, that's just impossible.

I am perfectly willing to change my mind if someone can explain how the AMP can overcome what I just explained.

I’m not fully up to speed, but I believe this is what the Aztec feature is supposed to address.

 

[jlow]

My understanding is the Aztec feature allows you to customize the machine to a specific batch of brass without having to send it in to AMP. It does not customize the machine to each piece of brass. I also think that the process used by Aztec destroys the brass that is used to get the number?

 

[dcali]

My understanding is the Aztec feature allows you to customize the machine to a specific batch of brass without having to send it in to AMP. It does not customize the machine to each piece of brass. I also think that the process used by Aztec destroys the brass that is used to get the number?

I don’t think it’s possible or necessary to require that level of precision in annealing. All you need is a consistent hardness. We’re already talking about a factor that is so far down the list that people can debate whether it’s needed at all. Trying to adjust for minor dimensional inconsistencies is kind of like measuring powder to .001 grains.

The way I see it, AMP is the only unit where they have quantified and measured their results and compared them to unannraled brass. Their machines appear to do exactly what is desired. Maybe torches are as good. I kind of doubt it simply because flame is not as easy to regulate as electricity. And maybe the difference, if there is one, is not significant on the target.

That said, i don’t anneal my cases and I don’t own an AMP. I’m just commenting from the perspective of the science/engineering involved. I reserve the right to be wrong, as always.

 

[jlow]

I think you missed my point.

You are exactly correct i.e. it is not possible or necessary to require that level of precision. The level of precision obtained by both the AMP and flame based annealer like the BenchSource is completely adequate.

The point is the AMP does not give you any better anneal for the double the price - PERIOD.

I guess for those who don't/can't deal with the flame or cannot set up a flame-based anneal, they would have to go the AMP route. But for the rest of us, it is unnecessary..

 

[6MT]

I have both AMP machines (Mark I & II). A big reason I bought one was being able to anneal indoors. Annealing with fire indoors is a non-starter in my particular situation. Even salt bath annealing would not work indoors for me. Electric induction annealing was the perfect solution.

I knew early on in my reloading career that working hardness affects brass life. Neck tension consistancy is also very important and I noticed this as well early in my career. Without annealing, after multiple firings (+5), I noticed neck tensions all over the place. Annealing gives absolute consistent neck tension. Consistency being the key.

An example of brass life I noticed after I began annealing is that for my magnum cases (.338LM), my brass cycles have increased from around 10 or 11 cycles, to well over 15. I even have some cases that have reached 20 firings. This is true for all calibres that I load for (6). The Lapua case is so good, add to that annealing, and you start seeing significant cost savings. Just another bonus to annealing.

For those who believe annealing is an unnecessary step, just look to my examples above. You're either in this for top quality results, or you're not. The inherent cost savings over time are a nice bonus. As far as increasing accuracy goes, yes I believe it helps. Neck tension consistency being the main reason.

 

[normmatzen]

For all the Nay-Sayers here, I have some comments.

You all are pretty correct.

Now, why do I anneal after every firing;

I started long range bench rest about 10 years ago. I might add when I was old enough to know better!
Anyway, I ended up shooting 6BRX and later also 284 WIN, I didn't anneal and I didn't use in-line seaters. I did find that cases had a finite life span!
So, I started sending out my brass for annealing every 5 firings.
Along came my in-line seater and force measuring press. I noticed quite a bit of variability in force needed to seat bullets.
By now I was using an Ohaus TS-200 lab
balance, custom LEE collett neck dies and short body dies for body sizing. So I figured it was time to start annealing. So, I chucked a metric socket into my drill-driver and dropped a case into the socket and spun it at a reasonable speed and put the neck area into a propane burner flame till I could just discern a slight reddish tinge in a poorly lit garage.

As a long term electronic engineer, the lack of process controlability irked me. so, then my first addition to this thread in the first page.

Now, with my Lab Balance, force measuring
press, decent dies and my Annie annealer, I am pretty sure I am addressing most of the variabilitiy in the loading process including getting required force to seat bullets at about 25 lbs for 6BRX and 30lb for 284 WIN. Plus I do things like match B-O dimensions.

The rest is up to me to pull the trigger.

The required accuracy in the process obviously varies with discipline. I seek Minute of Deer accuracy for my dear hunting rifle and ammunition (Although I am un-happy when it won't shoot 1" groups at 100yd!), 1 MOA for my K-31 for Garand matches and 0.25 MOA for my bench rest guns.
To be successful at these endeavors still requires proper trigger pulling control to be successful.
And THAT is why I anneal after every shot,
and for each of my guns!

 

[jawjaboy]

Mike's works for me too.