Case annealing

[harrygrey382]

I want to anneal my cases, mostly to increase case life. I'm getting about 30% split necks from Federal brass in my 243 after 4 loadings. I'm going to see if annealing gets more loads out of them. Also, it can't hurt accuracy to have more even neck tension.

I've read up about it a bit, and have built a turntable to rotate the the brass so the heat will be even around the neck while I hit it with a blowtorch.

My question is regarding temperature. I know I don't want to heat it very hot - well cooler than glowing. Looking at the photo below of split cases I tested on - which case is best? 2nd or 3rd from the right? 1st is not annealed, 2nd is a bit of heat - you can see the colour has darkened a bit aournd the neck and shoulder, 3rd is warmer - the neck and shoulder have taken on a copperish colour almost like rose gold. I'm thinking this is the colour I want? The last I heated the **** out of...

 

[Brithunter]

Harry 243 federal brass does nto appear to very good. I too have seen the necks split on the 20 I was playing with after the 3rd or 4th reload. Weighing the cases they are 12 grains heavier than the Remington R.P brass I am now playing with.

The classic way to anneal cases is to stand them in a dish of water with about 1.2 the case clear of the water and with a torch heat the necks until the turn red then knock the case over into the water. Job done.

Dry the cases some place them in the over at about 50 degrees to dry them out. I usually place them on top of the radiator for a day or so or in the direct sun in warmer times..

 

[Muir]

I was told an interesting method of annealing a while back tho I have never used it... but will try eventually. Hold the case in a common candle flame, horizontally, while rotating the case back and forth between two bare finger on the case head (not rim) area. When the case gets too hot to hold, drop it in bowl of water. Supposedly it works quite well. ~Muir

 

[JabaliHunter]

The classic way to anneal cases is to stand them in a dish of water with about 1.2 the case clear of the water and with a torch heat the necks until the turn red then knock the case over into the water. Job done.

It works - but I would say if it glows bright red you may be over-heating the brass.
Try some of this stuff http://www.waltersandwalters.co.uk/html/tempilaq.html
For info - this site contains lots of information too The Art and Science of Annealing

 

[harrygrey382]

Yes I've heard red hot is too hot. That site Jabail is what started me off in the first place. I found another good video for anyone that's interested - Annealing Brass In HD - ammosmith.com
Think I'm ready to give some a go now

 

[Brithunter]

Hmmm well the red is dull red and not a bright cherry red and it's the way I have annealed cases when they needed it for several decades. First started doing it with the turned 577/450 cases from NFDS as if you didn't they split on sizing. Turns out soemone had messed with the new dies at Fultons and mixed them up. NFDS did several sizes to suit the various chambers found in this chambering and my set was all miss matched. At a Bisley show I saw the chap who made them and he was a bit stroppy but did sort them out. I did point out that i just brought the dies from Fultons as is and only used them.

Hence I had to learn to anneal cases so as not to lose them as 50p a pop I think it was which was a horrendous price back them. The brass must reach a certian critical tempreture for the grain sturcture to alter.

 

[Brough]

Its not as easy as just heat up until red , I believe the temp is critical around 600 degrees from memory.
You also need a way of heating that only heats the neck,as that is the part you are trying to anneal.
Its no good using a flame thrower that heats up the whole case , a needle flame is required to concentrate the flame to the neck only.

I believe you can get wax type crayons that metal workers use that melt at various temps .

 

[DCG]

Don’t Know if its of any use and I know its a different metal, but an old coach builder I know used to anneal aluminium by covering the metal with soot from an acetylene flame and thereafter heating the metal to the point that the soot burnt off, apparently the point at which the soot burns is the annealing point for aluminium, probably isn’t the same for brass but might be worth a try. (I used to use acetylene lighter for blacking sights many years ago, don’t suppose any one does that now).

 

[Brithunter]

Actually it's very easy to heat until dull red using a propane torch I used to use the gas cannister ones. Using the tray o water stops the lower part of the case getting hot. Of course doing this in bright sunlight is not a good idea as you cannot see the colours properly. This really is not rocket science just basic heat treating infact ist was taught early one in City & Guilds Engineering.

 

[JabaliHunter]

Basically, its important not to heat the body of the case, only the neck/shoulder (which is the reason for heating the cases standing in a tray of water as stated above) and not to overheat the brass. I guess the potential damage relates to the relative pressure of the cartridge being fired after annealing.

From the article in the link above:

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.

Borrowed these pics (from carolinamarksman.com) to illustrate

 

[ads03]

I'm with Brithunter on this, its not rocket science and over thinking things can make a very basic job very difficult indeed.
I have done a hell of alot of work with brass over the years, not ammunition to be fair but brass instrument constuction and I can tell you heating to a dull red is the way to go every time,
Yes you can mess around with all the latest gadgets and temp indicators but the brass has a very cheap and easy to read indicator of its own, as soon as it starts to turn a dull red, stop, "SIMPLES". Providing your not using a torch fit for flat roofing you've got plenty of time inbetween dull red (perfect)and cherry red (to hot) so don't panic and Keep It Simple.

Hope this is of some help?

Regards

Ads

 

[sikadog]

If anyone is interested in the heat sensitive wax crayons they are made by a company called Thermographics from Deeside North Wales.

 

[NigelM]

I used to use Remington Brass in my 6mm06AI. The loads were pretty hot but I was splitting brass on 2nd firing. Finally changed to Norma brass. All problems dissapeared overnight. I am now pretty fussy about which brass i will use. The Norma's go 4 firings before annealing. I just take them to glowing green 1/3 the way down the case and knock over into shallow water to quench. I was told if it goes red you've gone too far. Seems to work alright.

 

[Brithunter]

I just take them to glowing green 1/3 the way down the case and knock over into shallow water to quench. I was told if it goes red you've gone too far.

Hmmm obviously the instructors at the Technical College running the City & Gulds course all those years ago didn't know anything then then and all the old text books on annealing and heat treating must be wrong too .

 

[Lee303]

For info - this site contains lots of information too The Art and Science of Annealing

Check out the rig for annealing cases in the picture on the first page! I am mighty impressed with that considering it's HOME built. Both that rig, and the one in the video actually rotate the cases within their holes in the carousel; nice piece of engineering.

Also, a few people are mentioning quenching the brass after it's been heated, which is not a method for annealing brass. Maybe the users are mentioning this simply to cool the cases for ease of handling.

 

[Lee303]

Hmmm obviously the instructors at the Technical College running the City & Gulds course all those years ago didn't know anything then then and all the old text books on annealing and heat treating must be wrong too .

Not with brass my friend. No need for red hot. Heating to red would make them as soft as a fine french brie!!

 

[Brithunter]

Not with brass my friend. No need for red hot. Heating to red would make them as soft as a fine french brie!!

Really and I had never noticed it ! I'll continue to do it my way thanks. It's worked when I needed it for the last couple of decades so I cannot see it sudenly not working now. Funny thing is that none of the necks or shoulders have collapsed as your suggesting so must be doing something right.

 

[Lee303]

Funny thing is that none of the necks or shoulders have collapsed as your suggesting so must be doing something right.

(Sorry, I never mentioned collapse...?)

I am sure your method works just fine. During your City & Guilds course I am sure you did learn how to correctly anneal brass, but your textbooks did not touch on annealing bullet cases. Of course, many brass components DO require annealing to red hot, brass bullet cases, however, do not. Heating to red hot will result in a much softer case than required, hence no real necessity for red hot. That's all I'm saying.

If you were to heat too much of a case to red hot (which you obviously don't since you still have eyes in order to be able to see your monitor/keyboard!), you're risking major case failure (probably resulting in serious injury). I would most definitely not describe this situation as collapse; brass explosion/disintegration would be closer to the result (a face full of super heated gas and possibly a few melted brass particals).

 

[Lee303]

I should have added that heating (any) brass to dull red (as mentioned above by ads03) will mean the temperature is around 480-510C, this may be good for trumpets, but far too hot for annealing CASES, and for safety reasons this brass should not be used (at least not by me, or anyone else I hand a rifle to). Again, I am most definitely not saying you won't get away with it, but it's a risk I am personally not willing to take.

We could go yet deeper (completely un-necessary) and talk about work hardening with each shot, this would "undo" your annealing and hence lengthen the life of an over-heated case. The variation from one rifle/case to another, how much work hardening a case has sustained, and the precise time/temperature of heat exposure during any one annealing process makes this simply ridiculous to discuss. So I won't even go there.

 

[Brithunter]

Really well seeing as how your mind is made up and closed it's pointless continuing.