annealing case necks(6.5x55)

T

tornado45

Regular
Rating - 100%
72   0   0
Location
toronto ugh!
What is the easist way to anneal case necks,do you need any special equipment I have a bunch of 6.5 that seem to have brittle necks when i resized some, the necks and shoulder ripped off in the die,the other brass i resized before was fine .The problem brass was marked ca and nny.
Thanks Tornado
 
A metal bread-loaf pan and a propane torch will do a quick and dirty job. Stand the cases in water that comes just below the shoulder, heat each neck to an even dull-cherry red with the torch, then use the head of the torch to push the case over into the water.

65% of the time, it works everytime.

-M
 
Doc M said:
A metal bread-loaf pan and a propane torch will do a quick and dirty job. Stand the cases in water that comes just below the shoulder, heat each neck to an even dull-cherry red with the torch, then use the head of the torch to push the case over into the water.

65% of the time, it works everytime.

-M
Click to expand...

Problem is in applying even heat all the way around the neck as well as the risk of overheating them. I hold them in my fingers and rotate them in the torch flame - your fingers will tell you when to drop them into a pail of cool water. Both methods will work once you get used to them. I know guys who aren't sold on annealing, but I know the difference when I get it right - velocity spreads get tighter.
 
I just light a candle and heat the case neck area while rolling the rim with my fingers until the rim(I reload rimmed cases) becomes too hot to hold, then drop it in some water to cool off. Candle flame is 600-1400 degrees F and annealing happens at around 650-700 degrees. So far, I have not lost a single case to date using this method, nor have I experienced any splits.
 
The method Doc M describes has been written up in magazines and reloading manuals for years and positively makes me shudder. It is a sure recipe for inconsistent heating and excessive heating of the necks.

sbtennex's method is better. Spinning the case in your fingers will give decent consistency. The problem is that the temperature at the neck when your fingers get warm at the head will vary immensely depending on how strong your flame is. The best success I have had so far was to count steamboats while holding the case in the flame. Try three steamboats, then pull out the case and let it cool for half a minute, then look at the neck and shoulder to see if it has taken on the colour of new military brass. If too dark, cut back half a steamboat, if too light, add half a steamboat. Repeat. Once you get it right, do the whole batch, heating by time, not appearance or feel.

Also, drop the hot cases on a damp towel instead of a bucket of water. That way you won't have to wait days or oven dry them before loading.
 
Spin the case between your fingers with the neck in a propane torch flame in a very dim or dark room. As soon as you see the faintest red color in the neck drop into water. Cherry red is to hot!
 
www.6mmbr.com

Type "Annealing" in the search bar there and read the article they have on the subject. It is a great article with some different ideas you may want to try.

I would direct link you to the article but the site is down for maintenance at the moment.
 
BattleRife said:
The method Doc M describes has been written up in magazines and reloading manuals for years and positively makes me shudder. It is a sure recipe for inconsistent heating and excessive heating of the necks.
Click to expand...

This is true - it takes special care not to overheat the necks using the pan-and-water method. I suppose I should have mentioned that.

-M
 
I put some templiac welding crayon just below the shoulder 650F I believe.

Cases are rotated in a propane flame until the crayon puffs off. Into a bucket of water.

I put the case into a long socket wrench to ensure the base of the case is shielded from the heat. Just the front 1/3 of the case exposed and only the neck in the flame.

I have noticed that cases do not heat up the same way so timing may be problematic. I believe that the crayon is quite accurate and consistent so use that to ensure case to case consistency.

Seems to work.

Jerry
 
Any welding supply place. Might not be in stock but easy enough for them to get.

I tried the paint first. What a PITA!!!!! don't go there.

The sticks leave little to no residue when it flashes off. I know that 650F is conservative as the colour change is not that strong. But I rather be under then over cause once it gets cooked, you got jello for necks.

Plus you have to put the mark away from the flame for obvious reason. I reason that by the time the mark flashes off, the necks are somewhat warmer. As long as it gets over 700F, it should anneal the brass.

I am going to try using two torches and not rotate the brass. It might be more even in heating up the circumferance of the necks?????

Jerry
 
FWIW - The nny brass (Privy Partizan) is poor. Very heavy walled, and the material is quite brittle. Even with annealing, its hard to work in the dies. I had some that had such a thick wall at the neck that the loaded round would tend to bind in the chamber - bad news...
 
I tried a variant of this:
I drag out my lead furnace, fill it to the top and turn it on.
While it heats up, I have all my clean brass DECAPPED with an universal decapper. It is important that the flash hole be open.
I dip and twirl the cases mouths past the shoulder in a small metal container (film container does) filled with very small ball bearings (very small lead shot will do) and molybden sulfur powder (moly). This coats the necks and shoulders inside and out with moly dry lube.
When my lead is hot and melted, I flux and stir it until it is clean as a mirror.
Now, holding the cases with my bare fingers, I dip the necks and shoulders in the molten lead; the hot air will escape by the primer hole, thus letting lead inside. Moly lube will keep lead from sticking to the brass.
When brass becomes too hot to the touch, I let it drop in a pail of very cold water at my feet.
Brass will be annealed just right.
Just make sure your brass is very clean and DRY before trying this.
Good luck!
PP.
 
I set up a number of 243 in a bread pan of water directly under the broiler in the oven. When the oven reached teperature I pulled out the pan, dumping the brass over and it was done. Dried them off in another pan at low heat in the oven. Seemed to work . . . comments anyone.
 
horseman2 said:
I set up a number of 243 in a bread pan of water directly under the broiler in the oven. When the oven reached teperature I pulled out the pan, dumping the brass over and it was done. Dried them off in another pan at low heat in the oven. Seemed to work . . . comments anyone.
Click to expand...

As a test, I once stood a single .308 case in a pan of water under the broiler of my oven. The rack was set so that the case was as close as I could get it to the element.

The case was marked with streaks from several Tempstiks, the lowest was about 260C, I think? Anyway, after almost an hour, not one of the markings showed that the target temperature had been achieved. I concluded that electric ovens cannot be used to anneal brass, unless maybe you have one that has a self-cleaning cycle.

PP, as much as I have heard about the lead pot method for years, you are the first person I have heard about actually trying it. I decided a few months ago that a variation of this must be the most controllable method of annealing, so I started collecting the gear I needed. I was actually thinking of doing the first trials with it today.

I bought a Lee Precision Melter and a Mastercraft digital multimeter with a thermocouple input. Here is the magic: don't use lead, use salt.

Nitrate salts (potassium nitrate and sodium nitrate, particularly) have melting points right around 300C. A 50-50 (atomic ratio) blend of the two can be made to have a melting point as low as 223C. The salts are stable up to well over 600 degrees. This is perfect for what we are doing. The molten salt is non-toxic and non-corrosive. Molten salts have been used as a heat treating media for almost a centruy, there was even a MIL spec for heat treating salts, including the KNO3-NaNO3 mixture I noted above for annealing copper and brasses (MIL-S-10699).

The only drawbacks I have encountered in my brief experiments so far ( I bought 2kg of potassium nitrate at a pharmacy and tried melting it over the stove):
- A bit of salt will stick to each case, and it is hard. The cases will have to be tossed into a bucket of water for a couple of minutes to dissolve the salt, then of course you will have to dry them
- When you are done and the salt has cooled, it will be a very hard block, not the easy to handle prills (tiny bead-like nodules) it started as
- These salts must be stored tightly sealed. If not, they will suck water out of the air until they dissolve themselves in a little puddle (this is called deliquesence). If they are left in the melting pot, this salt water puddle is sure to cause severe corrosion.
 
Since I opened my big mouth, I figured I hed better go ahead and fire up my new annealing setup. So, I gathered all the things I needed:
IMG_0247.jpg


The salt melted at 347C, and was clear as water. I had it deep enough to just barely immerse the neck and shoulder.

I tried a couple of times to hold the case by the head in my fingers, but my knuckles got pretty toasty, so afterwards I used a pair of pliers. I would hold the case in the salt for a count of 4 or 5 steamboats, then toss it into water. The water bucket is on the floor to reduce the chance any splashing water could make it into the pot. On a few occasions, after pulling the case from the bath at the 5 steamboat count, I would touch my finger to the case head. It was no more than comfortably warm. If I held my finger there, it was 2-3 seconds later that the case head became painfully hot. I did notice that cases that were immersed only a couple of seconds had a thick layer of salt frozen on them, while ones that were immersed a full 4-5 seconds did not, as I guess they got hot enough to keep the salt from freezing on them.
IMG_0253.jpg

I though it was interesting that at the hottest temperature I tried annealing, ~500, I was just starting to get some colour to the brass cases. 400 and 450 degrees had shown no colour changes to the brass at all.

The big advantage to this method is temperature control. I found that the Lee melter would hold the temperature in about a 5-8 degree range. When I started doing the cases, at a rate of about 6-8 per minute, the temperature dropped about 15 degrees and stabilized there.

I will add that I did not decap my cases, so they were just being heated from the outside. It will be interesting to measure the effects of this someday.

I ran my pot up hotter, just to see what it would do, and the salt started to fume or smoke at around 560C. I checked the MILSPEC and they pointed out that while the salt decomposes at 630C or so, it actually becomes dangerously oxidizing a bit before that and should never be heated over 590C. There are some serious warnings about violent reactions that can take place if contact is allowed with carbon, organic material or aluminum or magnesium metal while hot, expecially if the temperature exceeds 590C, so if you are thinking of repeating my experiment, drop me a note and I will forward you this document so you can read the warnings yourself.

The salt cracks like a brittle weld as it cools after it solidifies. I could hear it popping in the kitchen (oops, I mean "experimental laboratory facility") right up until a couple of minutes ago. Hopefully that will make it easier to remove from the pot.
 
BattleRife said:
I though it was interesting that at the hottest temperature I tried annealing, ~500, I was just starting to get some colour to the brass cases. 400 and 450 degrees had shown no colour changes to the brass at all.

I ran my pot up hotter, just to see what it would do, and the salt started to fume or smoke at around 560C. I checked the MILSPEC and they pointed out that while the salt decomposes at 630C or so, it actually becomes dangerously oxidizing a bit before that and should never be heated over 590C.
Click to expand...


Optimal Case Temperatures for Successful Annealing

Brass is an excellent conductor of heat. A flame applied at any point on a case for a short time will cause the rest of the case to heat very quickly. There are several temperatures at which brass is affected. Also, the time the brass remains at a given temperature will have an effect. Brass which has been "work hardened" (sometimes referred to as "cold worked") is unaffected by temperatures (Fahrenheit) up to 482 degrees (F) regardless of the time it is left at this temperature. At about 495 degrees (F) some changes in grain structure begins to occur, although the brass remains about as hard as before--it would take a laboratory analysis to see the changes that take place at this temperature.

The trick is to heat the neck just to the point where the grain structure becomes sufficiently large enough to give the case a springy property, leaving the body changed but little, and the head of the case virtually unchanged.

If cases are heated to about 600 degrees (F) for one hour, they will be thoroughly annealed--head and body included. That is, they will be ruined. (For a temperature comparison, pure lead melts at 621.3 degrees F).

The critical time and temperature at which the grain structure reforms into something suitable for case necks is 662 degrees (F) for some 15 minutes. A higher temperature, say from 750 to 800 degrees, will do the same job in a few seconds. If brass is allowed to reach temperatures higher than this (regardless of the time), it will be made irretrievably and irrevocably too soft.

Brass will begin to glow a faint orange at about 950 degrees (F). Even if the heating is stopped at a couple of hundred degrees below this temperature, the damage has been done--it will be too soft. From this discussion we can see that there are four considerations concerning time and temperature:
 
You must log in or register to reply here.
Back
Top Bottom