Case Neck Carbon Pattern

[Crosshair1]

Is it possible to determine from the pattern of carbon left on the outside of a fired case neck, that the case is in need of annealing?
The reason I ask is that I've only recently noticed that the more firings on the case without annealing caused the carbon to reach further down the neck/shoulder, once annealed the carbon is 'pushed back' close to the case mouth , showing a wavy pattern.
I anneal by hand with a gas torch & drill and until now haven't came across any method of confirming that annealing has taken place.
Thanks

 

[Dusty Stevens]

If you are an annealer you need to do it every time anyway

 

[Crosshair1]

Maybe I should have phrased it as the question "how do I know with certainty that my case is annealed?"

 

[Steve Blair]

Maybe I should have phrased it as the question "how do I know with certainty that my case is annealed?"

If you annealed it yourself.

 

[Straightshooter1]

Maybe I should have phrased it as the question "how do I know with certainty that my case is annealed?"

You can use a tools like this"

https://www.mscdirect.com/product/details/59647719?fromRR=Y

. . . or, you can anneal every time after firing as some people do.

 

[fyrewall]

If you are an annealer you need to do it every time anyway

After every firing/sizing, necks would be expanded and contacted making for work hardening. Brass is made harder by cold working and softer by annealing. Brass hardness is commonly measured using the Vickers scale - about 35 HV would be real soft and over 190 HV would be as hard as it gets. As far as I know, stuff softer than brass like rubber tires and rubber caster rollers use the Shore A scale. Having simple tools and possibly Templaq, annealing every time would be preferred since the Vickers hardness measuring stuff probably would not be available to re-loaders.

I don't know why the black stuff deposited in case necks would not be completely burned off by exposure to 2200 degree propane flame at the oxidizing end of the flame.

 

[T-shooter]

Is it possible to determine from the pattern of carbon left on the outside of a fired case neck, that the case is in need of annealing?
The reason I ask is that I've only recently noticed that the more firings on the case without annealing caused the carbon to reach further down the neck/shoulder, once annealed the carbon is 'pushed back' close to the case mouth , showing a wavy pattern.
I anneal by hand with a gas torch & drill and until now haven't came across any method of confirming that annealing has taken place.
Thanks

You probably should get some of the thermo sticks and see if you are getting the cases hot enough. I always see a change in the color of the case after heating. In the picture below, I used a small flame and put it only on the shoulder, never on the neck. That way the shoulder area softens without overcooking the neck which can't dissipate the heat as easily. The black streak is a 450° crayon and I stopped the heat as soon as it started to melt. On .308 cases I heat for about 7 seconds. For .223, about 4-5 with a 3/8" wide flame ( I flattened the nozzle a bit) and from about an inch away.

I had a box of Hornady .308 cases. They would not straighten until they were annealed. I loaded a few after prepping, full length resizing, and neck turning and even after firing I could tell the necks were off center. There was carbon only on one side of the neck and the other side was spotless. After they (and the ones not loaded) were annealed, they all looked normal.

 

[JASmith]

Is it possible to determine from the pattern of carbon left on the outside of a fired case neck, that the case is in need of annealing?
The reason I ask is that I've only recently noticed that the more firings on the case without annealing caused the carbon to reach further down the neck/shoulder, once annealed the carbon is 'pushed back' close to the case mouth , showing a wavy pattern.
I anneal by hand with a gas torch & drill and until now haven't came across any method of confirming that annealing has taken place.
Thanks

The answer may be in your question. If the carbon deposit reaches further down the case after each firing after anneal, one can use that as an indicator of how soon to anneal. I will admit I don’t pay attention to carbon deposits so can’t speak from experience.

Nonetheless, if one understands the anneal-work hardening sequence, then the logic becomes more clear. Starting with the annealed state, anything done, neck size, FL size, seat bullet, etc. cause some plastic deformation. That deformation causes the brass to work harden.

The rate of hardening is fastest at the start and then slows as the brass gets hard. That tapering of hardening rate is why I make sure I at least neck size after annealing. That gets the brass hardness a bit more consistent.

The hardness influences how soon the neck opens and seels against the camber wall. The difference in time influences how much gats can work up the outside of the case neck.

The 2nd or third loading should see even more consistent hardness and neck tension. After that, the risk of neck splits from overwork starts getting higher. How much risk depends on a lot of factors that are influenced by one’s chamber, reloading technique and hotness of loads.

Count yourself lucky if yu can track re,ativr hardness by observing the march of soot down the case neck. A lot of us are obliged to use the more arbitrary methods.

 

[JMayo]

I don't think there is any way to know except when bumping it bounces back.
Thus needs it. Other than that idk.

If shoulder is back too far and load is mild then carbon will make it past neck before case fully expands.

That Kinda sounds like case is hardened and doesn't expand as quick Hummm ...

But I'm shooting old brass that the shoulder is half a thou off and it seals up just like the new does. I have to change die setting for it by several thou to get bump to stay. So I'm thinking shoulder settings.