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.

 

[wvfarrier]

Case fracture would be my suspicion

 

[Ledzep]

@308pirate eat your heart out!

 

[Ledzep]

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.

The "alloy" is 70% copper and 30% zinc. Trace elements of whatever else is in there. Taking it dead soft doesn't appreciably change the chemical composition.

It's usually considered trash because the typically used hardness range "floats" somewhere well away from dead soft, yet also well away from 100% available cold work before fracture. When annealed back to dead-soft, there's no reasonable method to put cold work back into the neck to get it back to the typical grain size/hardness regime. Dead soft necks can be squished shut with your index finger and thumb. You could probably still "use" them, but results and handling are likely to be pretty lackluster.

 

[308pirate]

@308pirate eat your heart out!

i got nuthin'

 

[wcberry]

 

[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.