Annealing necks

Discussion in 'Reloading' started by Cruizin, Mar 11, 2007.

  1. Cruizin

    Cruizin Well-Known Member

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    Dec 25, 2006
    So I'm on load number 9 and I started thinking about having to reform some new brass for my 243 AI and read an article about annealing cases.

    Check it out...
    http://www.6mmbr.com/annealing.html

    I liked the last part of the article. After reading this I decided to give it a try. I chucked up the shell holder I have for my k&m neck turner and grabbed a torch I had laying aroud. I turned the drill on and spun the neck right at the tip of the blue flame that is about an inch past the end of the torch. I held it there for about 5-7 seconds. Basically right when or right after the flame changes to orange and the neck almost appears to start on fire. I then push the neck into water and the case head is only warm due to conduction. I think I'm doing it correctly and the necks seem to be noticably softer.

    Anybody that has experience annealing necks have any comments or suggestions?
     

  2. Joe Lee

    Joe Lee Member

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    Mar 11, 2007
    I have a 10" baking pan I fill with water till I can cover the shoulder of the case.In the room with the lights out I heat the necks till I see them turn red,then I tip them over the the water.Necks will last longer BUT check the case heads for cracks as the case ages from repeated firing.
     

  3. Centre Punch

    Centre Punch Well-Known Member

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    I can never understand why instructions on case neck annealing tell you to tip the case over in the water after heating it to dull red, doing so you are effectively quenching the case.
    To anneal any copper based alloy correctly it should be allowed to cool at room temperature after heating.
    The water in the tin is primarily there as a heat barrier, preventing the conduction of heat to the case body.

    Ian.
     
  4. Guest

    Guest Guest

    Hornaday sels a set of "pot chucks" that protect the lower half of the case, these are made of aluminum to conduct heat away from the base of the case.The way you are doing cases presents a danger of overheating the base of the case.
     
  5. Freebore

    Freebore Well-Known Member

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    I also use the baking pan method. fill the pan with enough water to cover about 2/3 of the case. I heat the neck with a 'custom' made 1/4" tubing with tiny holes around the inside connected to hand propane bottle till red, then kick it over in the water. This 'custom tube' made tube took some trial and error to get it togther. Before that I just used a standard torch and ran around in circle till I fell over..
     
  6. Black Diamond 408

    Black Diamond 408 Well-Known Member

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    There are many ways to anneal cases, one fact for sure, it has to be cooled fast. Cases should be put in some sort of cool water to keep the convection of heat percipitating into the case head area. Some use a lead pot and dip the cases into the molten lead and then quench. I use the pan of water method as described in an earlier post. Factory annealing machines do the same thing, the cases move through an assmbly line of flames to get the necks dull red in color, they then drop off the line and into a running water bath to quench cool.

    Brass or most non ferous metal are the opposite of Steel, annealing steel you heat and let cool very slowly. The more you work brass, ie, sizing, Neck forming, fire forming, results in work hardened brass that will crack or split. A lot will depend on the factory brass you are working with. When fire forming almost any AI type, annealing the brass first will increase case life.

    Here is a link to a annealing machine.
    Annealing brass cases

    I am doing a lot of neckdowns of the large 408C-T cases, bringing them down to 338 cal is a lot of neck movment, i pre anneal the cases to soften the brass, we dont want it too soft. After the neck forming is done i anneal one more time, this time a little farther down the case shoulder. Then fire form the cases. When your working with 2.00 brass everylittle bit helps in extending the life of the cases.

    Dave
     
  7. Centre Punch

    Centre Punch Well-Known Member

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    When i was learning how to hammer form copper plate i was taught to heat the plate to dull red, allow to cool and then drop it into a vat of copper sulphate solution.
    I therefore supposed that was the way to anneal all copper based alloys and is how i have done it since.

    Ian.
     
  8. Mikecr

    Mikecr Well-Known Member

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    We don't actually want to anneal. Annealed brass is ruined. We stress relief.

    Quenching is not needed for either. We sink heat from the base because no stress relieving is desired there.

    Brass is not affected in any way below 450deg. I lead dip stress relieve at 650deg to half way down the body over a 30sec period. Measuring the case head with the brass so immersed, has produced no more than 260deg. So dropping in water hasn't been needed. I do though, cuz I got no where to safely put oil smoking/hot brass, and I have to clean the oil out of the cases anyway. Hasn't seemed to hurt anything so far..But maybe I should allow longer cooling periods.
     
  9. Rooster 50

    Rooster 50 Member

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    Feb 8, 2007
    [ QUOTE ]
    I can never understand why instructions on case neck annealing tell you to tip the case over in the water after heating it to dull red, doing so you are effectively quenching the case.
    To anneal any copper based alloy correctly it should be allowed to cool at room temperature after heating.
    The water in the tin is primarily there as a heat barrier, preventing the conduction of heat to the case body.

    Ian.

    [/ QUOTE ]

    Not picking a fight Ian but, I have used the Hornady system for a couple years and find it to be very reliable. The main feature of the system is the tempilaq fluid used to paint a small stripe on the case just below the shoulder. According to the techs at Hornady You need to apply the blue tip of the torch to the juncture of the neck and shoulder. By the time the indicator stripe melts comletely at 475 degrees the area being heated has reached a temp close to 750 degrees. It then HAS to be quenched to prevent the heat from migrating to the WEB area and weakening it. If this area is annealed it leads to premature case head separation. This might sound like it's a lot different than your theory but I tend to believe the Manufacturer of brass when it comes to these things. No offense