Do you anneal your cases?

[tlk]

+1 ^^. It is called conduction.

Seems to me that the one thing that would put all of this to rest would be a knowledge of what the actual measurement of neck tension (ductility?) of a manufacturers brass is brand new AND how to measure it at the bench accurately. If someone knew how to measure it they could derive what it was out of the box for thier favorite brass and then be able to know exactly when each piece of brass has fallen out of the zone as well as whether or not their annealing method was adequate for thier purposes.


I understand that knowing for sure would be anathema because it would leave little to argue about on this topic (I think...), but does anyone know the details on how to do this?

 

[Trickymissfit]

It must be going beyond the shoulder on all Lapua cases as the visible color change is obvious.

I just looked at about a hundred Federal 30-06 cases a couple hours ago, and you could see the discoloration was kept in the neck. I've also go new and unfired Norma Weatherby brass that is exactly the same way. I would not fire a case that is discolored into the shoulder as it could be dangerous. Read what P.O. Ackley has to say about the subject
gary

 

[Pdvdh]

I've shot many casings that were annealed into the shoulder. Sometimes while fireforming cases I purposely anneal the shoulders to prevent casing splits when blowing out to fit larger chambers. No problems so far that have come to my attention.

Lapua brass that I have purchased is annealed past the neck into the shoulder area from their factory.

 

[Loner]

most folks I know anneal at 400 to 450 degrees to saturation. Five hundred degrees will probably extend heat into areas you don't what heat into. Six hundred degrees for sure when your looking at a .015" thick piece will destroy it. Nine hundred degrees is the start of the anneal process for steel (although on the low side), and eleven hundred degrees is about the norm. Most lead melts in the four hundred degree area, depending on the actuall alloy mixture. One of the problems with annealing brass or steel with a small torch is the heat concentrate, so a machine with a steady rotation would be the prefered method to get an even heat. Unlike steel where you quench in oil or another prefered medium (even heated oil is prefered) or simply allowing the steel to air cool in some cases (usually known as normalizing); you must shock brass to stop the heat transfer. Thus the use of ice water. Heat treating metal is not a guess work game, but precision science. Have you ever looked at something like a good 30-06 case and noticed the discolored blue area on the neck? If you take a good look at it you'll notice that the blue discoloring only goes about two thirds to three quarters of the way down the neck towards the shoulder. There's a reason why! Splits almost always start at the lip of the case neck, and thats the part that tends to harden first. You do not want heat to go all the way into the shoulder.
gary

Do you have any tech articles you can post links to? Everything I see says use a 650
or 660 heat crayon below the shoulder and heat the neck to blue without destroying
the shine of the case neck. That is about 750-800. In a pitch black room it will just
glow purple.

 

[Marine sniper]

Did he explain why he advised against it? His opinion/findings would be interesting to know.

He simply said it was not worth the effort. Did not do anything positive. I will ask him again when the rifle is finished, perhaps it has something to do with the fact we are using Lapua brass.

 

[Trickymissfit]

Do you have any tech articles you can post links to? Everything I see says use a 650
or 660 heat crayon below the shoulder and heat the neck to blue without destroying
the shine of the case neck. That is about 750-800. In a pitch black room it will just
glow purple.

the first time I ever heard about annealing cases was about twenty years ago, and at the time their ways of doing it were crude. Some guys used molten lead, and others used a torch. I even say guys standing cases up in water to their shoulders in an oven set at 400 degrees. I did nothing, as I couln't see this working. Later I was going thru some issues with split necks on a 22-250, and started to do some research. In one of my heat treat manuals they called out annealing brass in stages starting at 400 degrees and moving up to 600 degrees. They cautioned the user to be carefull not to actually burn the metal with over saturation of the heat. Now I'm more or less confused, as all my work has been with irons and a lot of space aged alloys. Rarely working with strait brass. To take it deeper, most brass alloys I worked with were bronze alloys (Ampco, etc.). So I made a few inquireys to see what other folks felt. Most of these guys were meatalurgists, and they all said the samething; exactly whatkind of brass alloy are you using? So I then took a few cases and cut them up, and made them flat. Sent them to the lab just to find out what I had. I soon learned that the cases were not strait brass, but an alloy containing several elements (one was close to being known as bronze!) Now I know what we had to a certain extent, and called Vito. He laughed at me, and said you already know the answer! (Vito taught me most everything I know about metalurgy). Vito said to start with a temp of about 450 degrees, and then send the piece to the lab for a granular structure test. Then do another about 50 degrees higher and one at 400 degrees. (remember the metal is very thin). All worked quite well for some odd reason! I then tried melted lead in a lead pot, and got very good results. The temp was about 430 degrees according to the read out. It actually did better than the otherways because the heat was very controlled and saturation was easy to controll. Then I said hey I can do betterand faster. So I tried dipping the necks in liquid salt for a few seconds. Instantly ruining each case! The lead pot was dangerous because of the quench in water. Well my welder said to try a temp stick in an open flame. I started with a 400 degree stick, and it worked very well. Later at a gunsmith's shop I see this 3/8th" thick plate with a bunch of pins sticking out of it. I asked him what it was, and he told me that's how he annealed cases. Guess what he used two temp sticks like I did; 400 and 450 degrees. I told him about my findings in the past, and he then told me what the lab had told me exactly to the main alloys in the brass. About three or four years later P.S. magazine showed a photo of one similar to his and mine (I made four different sizes). That's how I came about my method, but there's some more to this. I also learned that the thinner the metal, the more precise you have to be in the temp and saturation. I also learned that the water cannot be cold enough, and you will have to add ice cubes every now and then. I did try a -50 degree freezer once, but it didn't work.

The only serious tech articles on case annealing I've ever seen were in Shooting Times and P.S. several years ago. I seem to recall reading something written by Parker Ackley, and I'll check to see if I saved it for you. I'm sure there are others. Most of what I've learned was from others a hell of a lot smarter than I am, and also about 40 years of work (Vito was regarded as one of the goto guys in this country for 50 years).
gary

 

[Derek M.]

I just looked at about a hundred Federal 30-06 cases a couple hours ago, and you could see the discoloration was kept in the neck. I've also go new and unfired Norma Weatherby brass that is exactly the same way. I would not fire a case that is discolored into the shoulder as it could be dangerous. Read what P.O. Ackley has to say about the subject
gary

The only discoloration I've ever witnessed on any brass cases is Lapua, new cases. If you're concerns are correct, then Lapua has been jeapordizing safety for decades. Every new package of Lapua brass I buy has cases that look just like this:

I'm not sure what discoloration you are talking about on Federal cases or Norma cases since they send all of theirs from the factory, acid washed which eliminates any color changes from annealing, as far as I've experienced.

I've got a box full of new 300 RUM Federal brass, never fired, and about 200 Norma 6.5x284 brass, never fired, and there is no evidence of annealing on any of them (even though all new bottlenecked cases are indeed annealed). They are just acid washed so they all look uniform and "new."

When I'm done annealing my brass, they look almost identical to new Lapua cases. I'm satisfied with my results.

 

[Derek M.]

He simply said it was not worth the effort. Did not do anything positive.

He is incorrect on part 2, and he is welcome to his opinion as to part 1. I would agree with him if he's like I used to be and reload a case only 2-3 times and pitch it, in favor of using newer brass more frequently. For the purposes of extending case life as long as possible, annealing is essential.

If you look at the "run-of-the mill" sizer dies, el cheapos from RCBS or most any other make, Those case necks are squeezed substantially, as much as .015 or .017 from a fired case diameter, then they are subjected to an expander ball, then expanding another .001 or .0015 when a bullet is seated. Then when fired again, expanded even more to the extent it will do under pressure in a given chamber. Then it goes through all of that work hardening process again and again.

Work hardening on brass is bad ju ju over time.

 

[Loner]

Trickymissfit, you must be talking in centigrade. Almost all rifle brass is 70/30.
It is not hard to find websites with it's physical properties. Here are a few.
That is a delicate as I can put it. As I stated before there are a lot of guys heating
and quenching brass and doing little or no annealing.

Brass C26000

Making Brass Ammo Cartridge Cases

 

[tlk]

Loner, nice reply and thanks for the links. I can live with going up to 800. Not sure I want to go above, though. I know that below 700 is getting me nowhere with my brass.

But there is still the measurement question that nags at me: how on earth do you tell when they are all annealed the same? Maybe temp and time need to be different from lot to lot, brand to brand, etc. to get to the same annealing between cases. Is there some measuring device that can tell us that each case has the same (or different) "springiness" in it? Measuring based on ES is a kind of after the fact observation - it doesn't tell us what the characteristics were BEFORE, it is only a deduction by observation. And that sucks - at least to me.

 

[Loner]

Loner, nice reply and thanks for the links. I can live with going up to 800. Not sure I want to go above, though. I know that below 700 is getting me nowhere with my brass.

But there is still the measurement question that nags at me: how on earth do you tell when they are all annealed the same? Maybe temp and time need to be different from lot to lot, brand to brand, etc. to get to the same annealing between cases. Is there some measuring device that can tell us that each case has the same (or different) "springiness" in it? Measuring based on ES is a kind of after the fact observation - it doesn't tell us what the characteristics were BEFORE, it is only a deduction by observation. And that sucks - at least to me.

The heat crayon below the shoulder is the best method. A 650 or 660 crayon will
serve you well. Heating the neck with the brass spinning in a cordless drill is how I do
it. A 5/8" deep well socket is how I hold them. I just dump them on the concrete
floor, no quenching. You cannot use an IR gun as the emissivity of brass is so low the
guns will not allow you to set them that low. (Tarnished brass you can) Once you do
a few dozen cases you will have the time required down ( Have a clock in front of you)
for that particular caliber. Buy the crayon at a welding shop. I have to order them here,
we are a little backwoods so no big suppliers around.
I would say your lead method is the most consistent but a lot more trouble and I
was exposed to way to many toxins in my trade to add one more in life at this
stage. No boolits for me for the same reason.

 

[Trickymissfit]

Trickymissfit, you must be talking in centigrade. Almost all rifle brass is 70/30.
It is not hard to find websites with it's physical properties. Here are a few.
That is a delicate as I can put it. As I stated before there are a lot of guys heating
and quenching brass and doing little or no annealing.

Brass C26000

Making Brass Ammo Cartridge Cases

One brand of brass we checked in the lab showed a trace amounts of chrome and nickle in it (seems like it was Federal, but could be wrong). This kinda confirmed a couple of notions I had that Federal brass was much harder to form into other cases. Before that I was always told that it was because the case walls were thicker, but after cutting cases apart there was not all that much difference. I never knew anybody had the actual alloy make up for brass out there.

I never said anything much different than what everybody else did around here, except for the temp. That temp works well for me, and have never tried anything above 500 degrees. Quenching cases in ice water was something I was told to do by several folks out there, as well as more than one metalurgical engineer. The idea is to anneal the necks and not the body of the case, and a quick quench is there to prevent further heat transfer into the case body

Now you can heat just about anything hot enough to make it burn (even water). The temps vary per element, and somethings added here and there increase the burn temp of course. It's common knowledge that a bronze bushing used as a bearing will start to go south at a little over 300 degrees, and often will completely weld itself to a shaft at 400 degrees. Brass will not handle the temps that a pice of bronze will before the surface metal starts to let go. This is why they will often silver plate bronze when the temps exceed 250f. degrees. Whats this got todo with a case neck? It gives you a hint as what heat will do to brass or a brass alloy. There are brass welding rods that are made to melt at temps under 400 degrees (there is one that melts at under 250 degrees). These are used in special apps where you donot want to disturb the metal you are brazing (usually abrasive resistent steels). I would suspect that if you could look at the surface of a .015" thick piece of brass subjected to 750 degrees it would appear to be moving, or starting to go molecular. This is not melting, but when the metal is starting to let go. Yet I'd say the same piece of brass a quarter inch thick would be OK. I need to hunt up my heat treat hand book to see what they have to say on the subject as right now I'm on the verge of guessing
gary

 

[Trickymissfit]

The heat crayon below the shoulder is the best method. A 650 or 660 crayon will
serve you well. Heating the neck with the brass spinning in a cordless drill is how I do
it. A 5/8" deep well socket is how I hold them. I just dump them on the concrete
floor, no quenching. You cannot use an IR gun as the emissivity of brass is so low the
guns will not allow you to set them that low. (Tarnished brass you can) Once you do
a few dozen cases you will have the time required down ( Have a clock in front of you)
for that particular caliber. Buy the crayon at a welding shop. I have to order them here,
we are a little backwoods so no big suppliers around.
I would say your lead method is the most consistent but a lot more trouble and I
was exposed to way to many toxins in my trade to add one more in life at this
stage. No boolits for me for the same reason.

one thing about heating anykind of metal often overlooked is the actual chemical content of the metal. I've ran accross more than one piece that had beryillium in it! So do it in a well ventelated area. Cadium is another dangerous element. I've seen bronze and brass with lead in it as well as several other trace elements.
gary

 

[Pdvdh]

The heat crayon below the shoulder is the best method. A 650 or 660 crayon will serve you well. Heating the neck with the brass spinning in a cordless drill is how I do it.

I've tried temperature rated welding crayons and they are marginal at best IMO, because it's so hard to crayon a visible line onto the brass.

Brownell's and MidwayUSA both sell a temperature rated liquid that can be painted on the case neck shoulder area. I believe it's called Tempilaq. The stuff is rather expensive, but you don't need to use very much to determine the length of time to expose your case necks to your heat source in order to bring them up to the proper temperature. Then once you have determined how many seconds, simply time each casing with a large second hand clock in the background.

I've read where it's preferable to paint a line of the Tempilaq on the inside of the case neck rather than the outside, so it isn't directly in the flame and won't turn colors prematurely due to direct contact with the flame source.

Mind you, I've never purchased the Tempilaq product or used it myself. But I've researched it and made note of the reference information I've come across. If you're dead serious about obtaining the highest consistency and identifying the length of time to expose your spinning brass to the propane flame - I'd recommend the purchase and use of a small container of the Tempilaq.

As far as the correct brass casing annealing temperatures, everything I've read is consistent with Loner's and DerikM's information. Around 650F is the goal, heat source only applied to the neck/shoulder junction. I quench my annealed brass in a cold water bath, simply to stop the spread of the heat down toward the case head, but I have read many times that this quenching really isn't necessary, provided a hot flame source is briefly applied to the neck/case joint, and then removed from the flame source promptly.

The only thing I haven't done that I regret, is to have purchased some of the Tempilaq temperature sensing liquid. I believe painting a line of it inside the case neck, or on the outside of the case from the shoulder toward the case head, would be the very best way to determine the correct number of seconds to spin the case neck/shoulder in your flame source. After you have determined the proper number of seconds, then revert to timing with a second hand clock on all of the remaining casings. This would work slicker than snot and provide high confidence that you aren't under-heating or over-heating your cases.