Annealing brass ...

Discussion in 'Ammunition & Reloading' started by Gallo Pazzesco, Jul 31, 2008.

  1. Gallo Pazzesco

    Gallo Pazzesco New Member

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    What is your best method for annealing brass? What do you look for - in order to know when you have achieved the desired results?

    I try to anneal at least every fourth of fifth reloading. I should probably do it more often, but I am lazy at times.

    It is an art, a dark science to many - so I was wondering, how do you do it?
     
  2. robocop10mm

    robocop10mm Lifetime Supporting Member Lifetime Supporter

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    I take a shallow aluminum pie pan and put about a half inch of water in it. I stand the cases in pairs in the water. I use a Berzomatic torch and heat each pair fom one side then the other till the mouth glows red (about 10 seconds/side). This is not perfect but it apparently is sufficient as I neck .270 and .25-06 up to .312 to make 8 X 57 brass. I also make .243's and 7-08 into .308's. I experience about a 1% split case rate after annealing the brass in this manner.

    I guess it would be "better" to use some sort of a lazy susan to turn the brass, but my way seems to work fine.

    I do not anneal 5.56/.223 as it seems to be plentiful enough and I tend to lose them in the tall grass fairly regularly. Everything else from .308 - .45-70 gets annealed every third loading.
     

  3. matt g

    matt g New Member Supporter

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    I'd find out what the annealing temperature and time of yellow brass is then use the oven. Throw them in there on a baking sheet or something, turn the oven on to the required temp, leave it on for the required time, then turn it off and let the shells cool in the oven.

    That's how you anneal steel. I've also annealed copper the same way and used the same process to re-heat treat aluminum after welding and machining.

    I'd imagine that brass anneals somewhere in the 200º-250ºF range. That's where it happens for copper. As long as you take it to it's lowest critical temperature and hold it there for a little while, then let it cool slowly, you're annealing.
     
  4. robocop10mm

    robocop10mm Lifetime Supporting Member Lifetime Supporter

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    I don't know the specific annealing temp for yellow brass but I am willing to bet it is significantly higher than 250 degrees F. You should protect the base from the heat, thus the water as a heat sink. The base should remain hard while annealing the neck/shoulder area.
     
  5. matt g

    matt g New Member Supporter

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    Gotcha. I didn't know that you just wanted the neck annealed.
     
  6. cpttango30

    cpttango30 New Member

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    OMG DO NOT I repete DO NOT DO THIS. You will blow your face off well you wil atleast get powder burns on yur face.

    There are many ways. I just hold the base of the cartridge in my fingers and put it in the flame on my propane torch Place it right at the point where the inner flame comes to a point. If you burn your fingers then you got it to hot. I tried a drill as well works on smaller cases like the 223.

    The pan method is the best way unless you want to spend money on a anneling machine. They can go for $300 or more.

    http://www.6mmbr.com/annealing.html
     
    Last edited: Aug 1, 2008
  7. genie

    genie New Member

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    Annealing?

    Why all the annealing? To prevent split cases? In all my years of reloading, I have never resorted to annealing, never found a need to. Perhaps I just do not expect to re-use cases as many times as you fellers do, but then, in rifle calibers, case "stretch" becomes a critical issue for headspacing and proper bolt locking sooner than hardening of the cases presents itself to a high degree.

    If I'm going in the wrong direction, please guide me; I've done things the wrong way many times in my life!
     
  8. cpttango30

    cpttango30 New Member

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    I started doing it on the last few batches of 223 reloads. I was having a really bad problem with sooty necks and shoulders. It was the 2nd or 3rd reload so I desided annel them. The sooty neck issue is now resolved.

    Anneling can increase case life but after two or so reloads the necks become worked hardend. Then you annel them.
     
  9. robocop10mm

    robocop10mm Lifetime Supporting Member Lifetime Supporter

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    Annealing will add life to your cases. Brass gets harder and more brittle as it gets expanded, resized, fired, resized (worked). It is commonly referred to as work hardening. The bases/rims are intended to be hard but the necks need to be softer. This allows the brass to expand properly to seal off the chamber and release the bullet properly upon firing.

    I use it as I drastically change the dimensions of the case to use in a different caliber. .25-06 and .270 to 8mm Mauser. This puts much strain on hardened brass and will result in cracks if not properly annealed.

    All new rifle ammunition has been annealed at the neck after the forming process and before the final loading. You will notice the discoloration on the necks/shoulders of military ammo (5.56mm and 7.62 NATO) as they do not give them a final polish before loading. Commercial brass is polished one last time before loading so you do not see the discoloration.

    Annealing will prolong the life of the case. I anneal every other loading.
     
  10. Bob Wright

    Bob Wright Member

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    I annealed some .44 Magnum cases years ago, but found that I did not extend case life by any amount. I do examine and trim as required, and use the following practice: I load full power magnum loads for the first ten loadings, after that, I reserve those cases for milder or moderate loads. Several boxes of my brass are approaching having been loaded fifty times.

    [​IMG]

    This label is how I keep track of the number of times my brass has been reloaded.

    Bob Wright
     
  11. cpttango30

    cpttango30 New Member

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    I have never heard of anneling stright walled cases only bottle neck cases. I would think that anneling stright walled cases could cause the to seperate at the heat line.
     
  12. 1hole

    1hole New Member

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    Goodness.

    Case brass anneals, or softens, at something like 650-700F, not going to look it up now but that's under any visible red glow in a lighted room. Heating below the annealing temp will accomplish nothing, the brass won't be changed at all.

    Brass hardness comes first from the alloy and it work hardens more as we use it. Hardening actually changes the metal's grain structure. Annealing restores the hard, brittle grain structure to something close to the original characteristics, softer but with some springyness. Meaning, good annealing can extend the useful life of our cases If it's done right. Not only will the softer necks not split so fast, they will shoot better AND seal the gas pressue in the chamber better than work hardened brass can.

    I have a few .243 cases I've reloaded, hot in a factory sporter barrel with a sloppy chamber, as many as 15 times with no fear of a seperation. They have been annealed twice, and are due again, but they HAVE NOT been FL sized by "touching the shell holder" each time. If they had been conventionally sized some of them likely would have stretched and ruptured after as few as 4 or 5 loadings, as the magazine "experts" caution but don't explain why it's true. There is no justification for our cases to have that much stretch and seperations, even after many reloadings and, if they are properly sized, it just won't happen.

    Annealing has no value to anyone tossing brass after a half-dozen or so loadings unless it is brass that has been reformed from another cartridge. Normally, I find that rifle cases which are PROPERLY SIZED will last as long as 20 or more fulll power loads IF the necks don't split! Annealing after maybe each 5-8 loadings will reduce the incidence of neck splitting.

    Evenuatally the bodies will split and no annealing can help that. Attempts to soften the bodies would also soften the heads and allow them to rupture. That's not a pretty thought!

    Heating brass to a red glow, even in a darkened room, damages the alloy by burning out the zinc. Such over-heated brass is dead soft and will have no "spring back" at all. It destroys neck-to-bullet tension and that hurts accuracy. Proper hardness simply can't be restored after over heating.

    Using a HOT propane torch and holding the inner blue cone at the neck-shoulder junction while spinning the case in your fingers will do the job. That will limit heat creep towards the head because you WILL drop the case before excess heat migrates there! The hot cases should be dropped directly into a full water bucket. The water cooling is not part of the heat treatment, as it would be for steel, but to STOP heat from getting to the head and softening it there

    Neck annealing in a shallow pan of water will prevent head damage but it is almost impossible to get the brass temp consistant around the full circumfrence of the neck/shoulder in a pan so the heating is uneven. That can and will end up causing bent necks when it's pulled out over a sizer's expander plug - the softer side stretches more - so even heating is not a trivial issue.

    Spinning cases in the fingers seems to be best method unless you want to spring for one of the (expensive) motor driven annealing machines.

    You can somewhat gage the results of proper annealing visually. It's best to start with clean, polished brass. After annealing, the annealed surface will be discolored but should still have a shiney look. The soft blue blush should only reach a short portion of the case body below the shoulder, maybe an eighth inch. If the heated surface has a dead, flat look the zinc is gone and the neck is too soft.
     
    Last edited: Aug 6, 2008
  13. Bob Wright

    Bob Wright Member

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    One more thougtht on the subject:

    During the late 'fifties, .30 caliber M2 ammunition used stateside was arsenal reloads, mostly from Lake City Arsenal. These rounds had been annealed at the shoulder to neck area, evidenced by the discoloration in the area. A film showed the brass being passed by a stationary torch. No mention was made of quenching, and the film did not show that, if it were in fact done.

    So far as I know, only ball ammunition was reloaded, and that for CONUS use. All ammunition I saw overseas was AP, and newly manufactured.

    Bob Wright
     
  14. robocop10mm

    robocop10mm Lifetime Supporting Member Lifetime Supporter

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    You do not have to quench the brass after annealing, it just makes it easier to handle. It can be air cooled with the same results. Brass does not "temper" like steel so quenching does not effect the hardness/softness.

    Standing the brass in water is the easy way to protect the base from the softening effects of the annealing process. You could use some sort of a metal "heat sink" to do the same thing. I'm sure the Lake City process used some sort of heat sink that kept the bases cooler than the necks.
     
  15. Gallo Pazzesco

    Gallo Pazzesco New Member

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    Good stuff guys. Overall, the metalurgy of it makes sense.
     
  16. Darth AkSarBen

    Darth AkSarBen Member

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    I thought so too!