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I have never, ever seen annealing brass that works. Only when forming other calibers. You must soften to shape But to anneal necks might make you wish you never did.
 

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A funny thing I had happen long ago. There was no 6.5x55 brass so I formed from new 30-06 brass. I annealed each step and at the end, never getting red hot. Things went well and they shot good but I did not shoot for a long time after. Every case neck split just sitting in the MTM box. They were loaded of course and I don't know why.
Never anneal revolver brass, you will be sorry. Brass, if used can last, sitting seems to change things. My .44 brass from the 80's is sill going with one loss and They have been loaded 44 times. Some could be at the 50 mark. I annealed my 45-70 brass for my BPCR and it is OK but in my 45-70 revolver, they don't work at all.
Another thing I found was new brass split faster then used brass in revolvers. Every loss I had was the first sizing, few anyway but fired brass seems to stabilize.
Sometimes we look up and wonder. I think the more you use brass the better.
 

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Try Salt Bath Annealing

Hi all. I know this is a little necro posting, but I thought I have something to contribute. While researching the annealing process, I came across the video below from Ballistic Recreations on salt bath annealing. I did some research, and the cost of the materials (minus the small Lee melting pot,) was $90 (US) + shipping. I went ahead and ordered the kit and some extra salt. The little Lee melting pot was another $36 on Amazon, so my total buy in was about $150. Yesterday, I did about 100 prepped (clean, sized/deprimed, and trimmed) .22-250 cases using this method in about 10 minutes (not including warm up time.) When I first started, it was a little tricky getting the timing right, but once I got a rhythm going, it went smoothly and quickly, doing two cases every 10-12 seconds. The trick I found, was to use the "My Metronome" skill with Alexa (there are similar apps for iOS.) I set the beats per minute at 10 (every six seconds,) and process the brass this way: on the first beat put two shells in the holder, on the second beat pull them and drop in the bucket of water at my feet, grab two more, and on the 3rd beat, put the next two in. Repeat until done. I've tried the torch+socket on drill method, as well as stand the cases in a pan of water, but I liked this method the best. You can precisely control the amount of heat and amount of time for each case, and it's good for a whole range of cases (I use on .22-250, .30-06, and .45-70.) When I was finished, I simply rinsed and drained the brass, put them on a foil line baking sheet, and dried in the oven at 250°F for 1 to 1.5 hours. The salt is reusable, and once it cools, you put the cake back into it's jar. Hope this gives you all some ideas. Ed

https://www.youtube.com/watch?v=vwdTaDLz56Q
 

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I can do the same thing for **** you have in your kitchen. Plus the Benzomatic torch. Stand up brass in a shallow pan full of water. Heat the shoulder and neck until it glows a bit.....tip over. Done.
 

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RedlegEd,

Wow, that's hot! I've never before seen any contact annealing process recommended that was done at over 700-750°F. The brass stress relief you are trying to achieve (also called partial annealing in the brass industry) is a function of exposure time and temperature, so the 5 second time recommended in the video is shorter than the 20 seconds or so recommended for a 700°F pin in a soldering iron that you slip a case over. The main concern with higher temperatures is over-annealing and making the brass too soft and weakening it. Ironically, that causes splits to occurs with fewer subsequent reloadings than they would with correctly annealed cases, forcing you to re-anneal sooner. If you have to anneal more than once every five reloads to prevent splits, that's an indicator you are overdoing it. If you are holding for 12 seconds rather than the recommended 5 seconds, that's a concern.

The chart below is for 1 hour heat time, so the temperatures are all low, but the optimal time shortens exponentially as temperature goes up. This is why the makers of the expensive AMP machine test individual cases by headstamp and chambering to figure out the optimal exposure time at the higher temperature their induction heater imposes on the case.



Incidentally, the Lee pot thermostats have never been very tightly thermally coupled to the pots. The control on the one I have wanders about 50°F. I long ago hooked it up to a cheap PID controller. It appears the thermocouple used in the video and that you have is a standard K thermocouple. You can get Chinese PID controllers inexpensively on eBay that will work with that, and they have readouts of both the actual temperature as well as the control point, so they serve as the thermometer as well as the controller.

Here's one for $20 complete with 40A SSR (solid state relay) and heat sink, plus a spare type K probe (not suitable for your salt bath, as it has a 400°C limit so it would be relegated to other things, but it will work with your salt bath thermocouple). You would just set the Lee thermostat on maximum and let this device take over control (note that a bit of wiring is required). Assuming it is the controller shown, it is an auto-tuning PID controller, meaning you will have to let it play with the heater and bath a bit to find the proportional gain term and the integral and derivative time constants needed to achieve maximally flat control. If that is all space talk to you, it might be a challenge, though you don't actually have to know what those terms mean to use one of these. The manual is here.
 

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i built one of the drum type annealers where the case rolls in a drum while the torch heats it. The drum speed is adjustable for how long the case stays in the heat. Haven't used it a lot,But thought it worked really well. Curious if anyone else used this method.
 

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RedlegEd,



Here's one for $20 complete with 40A SSR (solid state relay) and heat sink, plus a spare type K probe (not suitable for your salt bath, as it has a 400°C limit so it would be relegated to other things, but it will work with your salt bath thermocouple).



FWIW these controllers are fine but the SSR rated 40a is actually a 16a device internally. I saw a vid (https://www.youtube.com/watch?v=DxEhxjvifyY look at about 2:30 he tore down a "25A" which had a 12A rated SCR) about this and tore down A 40A I had bought and confirmed it. Most cheap chinese sourced items are counterfeits in some way like lithium batteries that are simply relabeled under capacity batteries.
 

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To enhance case life.
 

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To enhance case life.
Which might be considered a safety concern when using "previously loaded brass".

This is a really good thread GuyKickInIt. Sucks that photocraponit decided to go bellyup, but still well worth reading the whole deal.
 

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On the subject of annealing, what is the danger of letting the brass get too hot?

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Case heads have to be hard, as this increases their tensile strength. If they are soft, rifle pressures inflate them like putty and they can blow out under pressure. When they do, this rapidly escaping high-pressure gas will normally split a rifle stock and often damages the bolt face and wrecks the magazine under the receiver into the bargain. For this reason, ovens are never used to anneal finished cartridge cases.

Full annealing softens even necks and shoulders too much to hold a bullet well and to resist deformation during seating. We do not want full annealing. What shooters need is what is called partial annealing in the industry. Technically it is just heating to the point work hardening stress is relieved, but not enough to change grain structure or weaken the brass appreciably. As the graph I posted shows, that stress relief begins slowly (one hour applied heat time frame) at about 250°C (482°F). As temperature rises, it appears to roughly obey the same law chemical reactions do, with the time halving every 10°C (18°F). An approximate formula for the stress relief time needed is:

Where:

t is the time in seconds and
T is the temperature in °C

t = 115,200 / 2^((T/10)-25)


Where:

t is the time in seconds and
T is the temperature in °F

t = 115,200 / 2^((T/18)-26.778)


So, if you heat the neck to 700°F instantaneously, the required stress relief time will be:

t = 115,200 / 2^((T/18)-26.778)
= 115,200 / 2^((700/18)-26.778)
= 115,200 / 2^(12.11)
=115,200 / 4424
= 26 seconds

Realize that at 718°F this drops to 13 s, and at 736°F it drops to 6.5 s, and at 754°F, it drops to 3.25 s. This rapid change in rate explains why you see so many very different annealing times.

The other complication is that you don't normally reach the temperature instantly. You heat gradually and at each temperature along the way some portion of the stress relief time passes, so some percentage of the annealing occurs. Thus, by the time you reach 700°F you no longer need the full 26 seconds. Also, if you use a temperature indicator, it takes time for heat to flow into it and melt it, during which the actual metal temperature overshoots, going to a shorter stress-relief time. So the above formula isn't necessarily useful from a practical standpoint unless you are controlling annealing very closely. Even then, it's for 70:30 alloy, and not all cases are made from that.

At one point I put a thermocouple in the bottom of a 30-06 case primer pocket and proceeded to use the gas flame on my stove to anneal it. I left it on the heat until colors changed rather noticeably and found the head got nowhere near a dangerous temperature. Still below the boiling point of water. If you expose only the neck and shoulder to your heat source, the case does get hot behind it, but it is also losing heat to the air like an inefficient heat sink. So you don't really need to worry a lot about it. I was unable to get the 30-06 head hot enough to be problematic even with no quenching.

Quenching mainly just lets you handle the case sooner. It was unnecessary for head temperature safety in the test I did. If you are annealing very short cases where heat flow to the heads may be more problematic, you can use the old trick of setting them in a dish with water that covers the heads and up about halfway to the mouth, and then use a torch to heat the necks until they start to turn color or use a temperature indicator. For quick handling, you can knock them over into the water, but if you have enough space between them so you don't heat more than one at once, it isn't required.
 
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Annealing cases

Thanks Nick for the info, I used a Map Gas torch, tip of torch about 2'' from the chase when it was in water and rotated the case about a four count. Needed to soften the cases so the necks dont split.

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You can quickly get them warmer than necessary with MAPP gas or an acetylene torch. I'll let you guess how I know. If they are getting red they are generally over-annealed and softer than necessary and weaker. One of the effects of that is, ironically, having to anneal more often because the weakened brass fatigues more rapidly. A well-annealed case should be able to go ten reloads without further splitting, but if you have to anneal every third or fourth time to prevent splits, you are getting the brass too hot.
 
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