Annealing

[wjm1000]

I have a question on over annealing.
Why is the brass considered trash if it's over annealed to a dead soft condition in just the neck shoulder junction? I'm aware that some of the alloys are burned off when the necks are over annealed. But don't know why that would make them unsuitable to reload. Is it because there would insufficient neck tension or it could possibly cause an unsafe condition and cause the neck to separate from the case body?

Any insight will be appreciated.

 

[SSchnd]

Annealing, things to consider, when we anneal we change the case metal properties again to a softer state but only in the neck and shoulder area. We do not want to anneal the case itself in a way we damage that body.

What happens if one over anneals the correct area, we cook the case body beyond 450degrees F we are just expecting an incipient case separation.

I would not load OVER Annealed brass, we expect too much precision and annealing is helping up with neck tension uniformity (needed) as well as longevity (benefit).

When I anneal I do a test of case or three using 750F Tempilaque on the case mouth (inner) and 450F on the case body (rim to shoulder) to make sure my dwell time (using a Giruad gas unit mind you) to make sure I have properly annealed the neck/shoulder and not cooked the case body.
I do not want the 450F heat paint burnt away any more than may upper 3/4 to 1/2 way down the case body.

Hope this helps. Ned should be along here shortly to put it more eloquently.

 

[MikeRu]

Not sure how over annealed it was, but you can try to work harden using a mandrel to mimic the neck expansion that occurs when fired, and then resize, repeat this cycle several times and then see if your seating pressure is restored using a force pack guage such as from K&M.

 

[gunsandgunsmithing]

I have a question on over annealing.
Why is the brass considered trash if it's over annealed to a dead soft condition in just the neck shoulder junction? I'm aware that some of the alloys are burned off when the necks are over annealed. But don't know why that would make them unsuitable to reload. Is it because there would insufficient neck tension or it could possibly cause an unsafe condition and cause the neck to separate from the case body?

Any insight will be appreciated.

As long as it's contained to the neck area, I don't think it's a safety issue but yes, if it's dead soft, it'll have little or no neck tension. The only way to re-harden it is to work it.

 

[Webster]

I have a question on over annealing.
Why is the brass considered trash if it's over annealed to a dead soft condition in just the neck shoulder junction? I'm aware that some of the alloys are burned off when the necks are over annealed. But don't know why that would make them unsuitable to reload. Is it because there would insufficient neck tension or it could possibly cause an unsafe condition and cause the neck to separate from the case body?

Any insight will be appreciated.

Take a case you didn't anneal and squeeze the body hard with pliers, do the same with an annealed case. I think you will find it takes the same effort to sqeeze both. 750F is a complete made up garbage number to anneal to. No-one knowns who made it up. Zero annealing takes place at 750F even for minutes. I have done accurate annealing studies at work and saved every study reported by a lab or research group I could find. The AMPS website has many good articles. . No-one believes real data. If you heat a neck until yellow color comes off it does not means Zn is being burned off. I have the article somewhere.

Illinois University Metallurgy Dept. Annealing Study (annealed in a furnace at constant temp)




My annealing study data. Necks were sectioned from the case and lowered into the furnace at a constant temp on a nichrome wire thru a small hole. The shortest time was 15 sec. since I didn't know how long it took to reach temp. If it doesn't anneal at 15 sec. it cannot anneal at 1 sec. Also did samples at 5 minutes for comparison.

 

[Straightshooter1]

I have a question on over annealing.
Why is the brass considered trash if it's over annealed to a dead soft condition in just the neck shoulder junction? I'm aware that some of the alloys are burned off when the necks are over annealed. But don't know why that would make them unsuitable to reload. Is it because there would insufficient neck tension or it could possibly cause an unsafe condition and cause the neck to separate from the case body?

Any insight will be appreciated.

It is possible to burn zinc out of the alloy if you get it hot enough. The melting point of zinc is ~ 785°F, but that's not a temperature that'll cause it to come out of the brass alloy. You'd have to melt the brass, which takes ~1700°F, then the zinc would boil off.

If you get the brass fully annealed it will not have any spring back or holding power other than a little friction. A neck that soft will allow the bullets to move in the magazine due to recoil and in case of semi-autos, even the action the bolt closing can move the bullet. So, that's one issue. The other is, and more importantly, the neck not having any spring back will tend to freeze the case in the chamber as the neck is forced against the chamber where a case simply can't be extracted.

A fully annealed case neck doesn't really have an issue for separating from the body as the bolt holds everything in place. It's just that ejection issue that's the problem.

 

[Triple BB]

Have you done Vickers testing on cases annealed with a torch. And how does torch annealing compare to induction annealing.

 

[Webster]

It is possible to burn zinc out of the alloy if you get it hot enough. The melting point of zinc is ~ 785°F, but that's not a temperature that'll cause it to come out of the brass alloy. You'd have to melt the brass, which takes ~1700°F, then the zinc would boil off.

If you get the brass fully annealed it will not have any spring back or holding power other than a little friction. A neck that soft will allow the bullets to move in the magazine due to recoil and in case of semi-autos, even the action the bolt closing can move the bullet. So, that's one issue. The other is, and more importantly, the neck not having any spring back will tend to freeze the case in the chamber as the neck is forced against the chamber where a case simply can't be extracted.

A fully annealed case neck doesn't really have an issue for separating from the body as the bolt holds everything in place. It's just that ejection issue that's the problem.

Fully annealed is

It is possible to burn zinc out of the alloy if you get it hot enough. The melting point of zinc is ~ 785°F, but that's not a temperature that'll cause it to come out of the brass alloy. You'd have to melt the brass, which takes ~1700°F, then the zinc would boil off.

If you get the brass fully annealed it will not have any spring back or holding power other than a little friction. A neck that soft will allow the bullets to move in the magazine due to recoil and in case of semi-autos, even the action the bolt closing can move the bullet. So, that's one issue. The other is, and more importantly, the neck not having any spring back will tend to freeze the case in the chamber as the neck is forced against the chamber where a case simply can't be extracted.

A fully annealed case neck doesn't really have an issue for separating from the body as the bolt holds everything in place. It's just that ejection issue that's the problem.

There are different degrees of annealing. Based on the Illinois University data you have to be 1 hr. @ 430C to reach dead soft.

It is possible to burn zinc out of the alloy if you get it hot enough. The melting point of zinc is ~ 785°F, but that's not a temperature that'll cause it to come out of the brass alloy. You'd have to melt the brass, which takes ~1700°F, then the zinc would boil off.

If you get the brass fully annealed it will not have any spring back or holding power other than a little friction. A neck that soft will allow the bullets to move in the magazine due to recoil and in case of semi-autos, even the action the bolt closing can move the bullet. So, that's one issue. The other is, and more importantly, the neck not having any spring back will tend to freeze the case in the chamber as the neck is forced against the chamber where a case simply can't be extracted.

A fully annealed case neck doesn't really have an issue for separating from the body as the bolt holds everything in place. It's just that ejection issue that's the problem.

Cartridge brass melts at the melting point of brass, not the melting point of Cu or Zn. Based on the University of Illinois data to reach full anneal you have to anneal about 1 hour at 450C (874F). I do torch annealing and never took samples to work to check. I'm retired now. I anneal with a torch until I just see red color on most of the neck. I feel I cannot go any hotter. I don't care if it's just stress relieving or how much it's annealed. My varmint rifles shoot under 1/2" and I have about 20 reloads on a case. Queezing the necks of torch annealed cases with pliers they have the same toughness and resistance to deforming the neck as queezing an unannealed case. This indicates to me that my procedure does very little to reduce the hardness. That's good enough for me.

 

[Straightshooter1]

Fully annealed is

Typically, that means or suggests "dead soft".

There are different degrees of annealing. Based on the Illinois University data you have to be 1 hr. @ 430C to reach dead soft

OK, as long as one understands that whatever degree we're talking about, it all still a function of amount of heat over time.

Cartridge brass melts at the melting point of brass, not the melting point of Cu or Zn. Based on the University of Illinois data to reach full anneal you have to anneal about 1 hour at 450C (874F).

I didn't suggest that brass melts at the temperature of Copper or Zinc. Copper has a higher melting point than brass and Zinc has a much lower melting point. Brass melts at ~1700°F, but just exactly what temperature brass will melt will vary depending on the its composition. Various brass will have various amounts of zinc as well as various amounts of other metals (e.g. Chromium, Iron Silicon).

I do torch annealing and never took samples to work to check. I'm retired now. I anneal with a torch until I just see red color on most of the neck. I feel I cannot go any hotter. I don't care if it's just stress relieving or how much it's annealed. My varmint rifles shoot under 1/2" and I have about 20 reloads on a case. Queezing the necks of torch annealed cases with pliers they have the same toughness and resistance to deforming the neck as queezing an unannealed case. This indicates to me that my procedure does very little to reduce the hardness. That's good enough for me.

Similarly, I flame anneal and look for the start of a red glow in a darkened room. Brass begins to glow red at ~1000°F and so I like that for the speed to getting the brass to the level of annealing that I like. It typically takes about 4-5 seconds to get to that glow, but the brass doesn't stay at that temperature long as when it just starts to turn that color it's only a fraction of a second as that's the point where the case is dropped out of the flame. I don't know, nor do I care, what the exact hardness is. But I do know my cases are softer than heating them to what's often been suggested (like 700 -800°F), as I can distinctly feel the difference when seating . . . and I also get better consistency with neck tension and shoulder bumps. I also get very good case life.

 

[Mulligan]

Where is @Riflewomen?

 

[Gundog]

Interesting results from Eric Cortina over annealing..

 

[boltfluter]

Interesting results from Eric Cortina over annealing..

Wait, what? Seems as though annealing time is not that critical. Maybe! How "not" to do a scientific test. Lol!
Paul

 

[rwj]

Where is @Riflewomen?

Apparently she moved on to other endeavors… believe she posted some pics of a plane she constructed!

 

[Mulligan]

Apparently she moved on to other endeavors… believe she posted some pics of a plane she constructed!

Miss her posts


Good for her though!

Thank you

CW

 

[Webster]

Wait, what? Seems as though annealing time is not that critical. Maybe! How "not" to do a scientific test. Lol!
Paul

What's happening is it doesn't matter much what the temperature is because it takes time at temp for annealing to take place. At just about any temp practically no annealing takes place in a couple seconds at temp. It's time at temp and we can only flash anneal. Look at the Illinois University chart. Even minutes at 450C the hardness only drops a few hardness values. Whether it's a torch or induction heating the longer heat is applied the hoter the brass gets. We have to stop before it gets too hot. We cannot hold at temp like a furnace anneal.

It's real simple anneal till the neck gets red and stop, you cannot do any better than that.

 

[SeabeeKen]

This would seem to suggest that heating the body of the case above 450 will not harm anything. I will contiue to anneal normally as I do notice a more consistent seating force.
With that said, many years ago, before I ever heard of annealing, I shot brass until necks cracked and the rifle grouped the same from the day the brass was new until they cracked.

 

[Webster]

This would seem to suggest that heating the body of the case above 450 will not harm anything. I will contiue to anneal normally as I do notice a more consistent seating force.
With that said, many years ago, before I ever heard of annealing, I shot brass until necks cracked and the rifle grouped the same from the day the brass was new until they cracked.

Look at the chart info.

 

[Webster]

It is possible to burn zinc out of the alloy if you get it hot enough. The melting point of zinc is ~ 785°F, but that's not a temperature that'll cause it to come out of the brass alloy. You'd have to melt the brass, which takes ~1700°F, then the zinc would boil off.

If you get the brass fully annealed it will not have any spring back or holding power other than a little friction. A neck that soft will allow the bullets to move in the magazine due to recoil and in case of semi-autos, even the action the bolt closing can move the bullet. So, that's one issue. The other is, and more importantly, the neck not having any spring back will tend to freeze the case in the chamber as the neck is forced against the chamber where a case simply can't be extracted.

A fully annealed case neck doesn't really have an issue for separating from the body as the bolt holds everything in place. It's just that ejection issue that's the problem.

Extremly unlikley anyone is annealing to a very low hardness level. It takes long time at high temp. Look at the posted charts.

 

[47WillysGuy]

7-9 seconds in the flame at the case body and shoulder junction, when the case neck turns red orange, remove.

The flame is directed at the case body and shoulder junction. This allows a softened (annealed) neck and shoulder which when the case is full sized the headspace difference is about 0.001”.

 

[2UP]

Does it matter how long you wait to resize after annealing? Can you anneal one day, then size another?