Over-annealing your brass?

[350JR]

This is somewhat out of my wheel house so ......HELP?

I keep reading about "over annealing" your case's neck and the shoulder area.

Just what exactly happens to the brass's integrity (and how/why if possible) if it's actually OVER annealed.

I can see where heating the neck TOO LONG will heat up parts of the case one would prefer to not get very hot but I'm at a loss on what happens to brass if "over" annealed. It's not like we're going to get to the over 1650 F. degree melting temperature that is generally given to brass.

I've stuck to the old (cheap) hand held (with cool, wet rag) and a candle or lighter for some half a century and I've seen FEW cracked necks, zero neck shoulder separation. Almost invariably I end up trashing cases due to loose prime pockets but it takes a LOT of use to get to that point.

I'd like to update my annealing game for the single reason of wanting to do my best at getting case necks to be as close to being same in all aspects (but realize, like almost everything in hand loading, that "the same" is a figment of our imagination) All things are NEVER entirely equal but it's a goal to shoot for such, IMO.

Not actually (no offense) looking for "how to do it", the question is purely this:

WHAT HAPPENS to over annealed neck brass and how is it recognizable? I'm about 90 percent convinced that, whatever it is, I'm not able to OVER do it in the hand held / open flame method but I also realize that what I've used is hardly the most consistent.

Any links or photos concerning over annealing.......are appreciated.
God Bless

 

[Nimrod84]

Best I can offer is http://www.6mmbr.com/annealing.html. Part way down the page they address over-annealing.

Big thing is that over-annealing the necks causes the brass to lose its strength, this could cause catastrophic failure if the heat goes to low into the body; but if lose of strength is confined to the neck it will cause low neck tension resulting in loose or wobbly bullets. I do not know of a indicator that the body has lost its strength, some guys will imprint case or two with a known / repeatable force (automatic center punch) to make sure the imprint remains about the same as virgin brass. If the brass is imprinted a lot more than the control brass, than the batch gets recycled / tossed. I think the most common way is to use TempilStik while annealing.

https://bisonballistics.com/articles/th ... -annealing has some info on the mechanics, but I think the 6mmbr link is more usable.

 

[ShadeTree]

I'd say with near 50 yrs in, your method is working.

Far as over annealing. Brass might melt and be destroyed at 1650, but there's other metal alloys in there that flash off and change the structure at a much lower temperature. Also like was stated above the middle section of the brass you don't want to be annealed. And not to tell you how to do it, but just to explain how I know when to quit using my method. I use a hotter flame then you by using a handheld torch at a low setting and the case is spinning slowly in a socket on a drill. As soon as the brass color changes and starts to flash color down the neck and to the shoulder I remove the flame. Usually 3-5 seconds with how I do it. You get that brown, silver, maybe some hints of light blue, mixed colors. With the line stopping just below the shoulder. Any purple color or deep purple and it's gotten too hot. At least for me.

Getting it hot to enough to be annealed but also making sure I'm not overdoing it by paying attention to the time and look of the case I'm looking for, has worked for me. But that's the line I stop at, others might take it farther and some might not go that far.

 

[mo381]

I use the same process as Shade tree. Small torch, rotating the case slowly in a socket until the neck/shoulder start to turn dull, off color.

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[Thebear_78]

Part of the reason I went with salt bath annealing was you can’t heat it over a set point. The salt only gets 550 c°


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[jimbires]

over annealed brass should act dead soft , no spring back at all . properly annealed , if you would very very very lightly squeeze the case mouth with pliers , you should be able to see it spring back a little when you lighten pressure on the pliers . I'm only talking squeezing the case a few thousandths .

over annealed should not spring back from the pliers test . I also think you should be able to tell when seating the bullet . maybe even when sizing when pulling the expander through the neck , or mandrel neck sizing , resistance should feel less .

trying to anneal by color hasn't proven to work for me . some of my cases do not show any sign of being heated , other makers brass show color . if I anneal brass that has not been cleaned of oil , it looks way over done before the annealing has started .

I suggest you try some 750* tempilac liquid . paint the inside of the case neck , and let it dry . then heat until it starts to melt .

 

[TackDriver284]

Jim, Another method I started to use for the first time the other day,,, instead of inside the necks ( its a hassle cleaning it out once it hardens after anneal test) I put a layer of 650 degree Tempilaq from the shoulder / body junction a quarter of the way down, and a layer of 450 degree Tempilaq ( next to the 650 degree layer )from the shoulder / body junction down close to the base and let dry. I anneal until about one eighth inches of the 650 degree melted from the shoulder / body junction down ( not on neck ) and the 450 degree only about one third ( almost halfway) of the way down. Does it sound about right? Does the inside of the neck give better accurate results than this method? I learned this method from You Tube.

If you use Tempilaq inside the necks, sometimes I feel more pressure sizing ( expander ball or mandrel running over inside necks ) and seating bullets than cases without Tempilaq inside the necks, some reside has left behind I missed cleaning 100% out, what do you use to completely remove all that burnt residue? I just wrap a bit of steel wool around a worn bronze brush chucked inside a drill, only thing worries me is removing some brass with steel wool may reduce some thickness to the necks and get uneven neck tensions. Am I being too anal? :wink:

 

[jimbires]

Mark , your tempilaq technique is probably about right .if I had some 650* I'd do a little testing for you . tempilaq is a pain to clean up , so I have saved all my old brass , instead of throwing it away . I now set up on this old brass , then I don't use tempilaq on my good brass . the reason I put it inside the neck is for protection from the torch flame . it seems as soon as the flame hits it the templiq flames up and I really can't tell what's going on . I'd too be Leary on using steel wool every time , it could be removing more brass than a guy would think . I don't like to think of me being to anal , so I call it attention to detail ! HA