Almost everyone who anneals their cases finishes the job by dropping it in water.. Isnt this the exact thing that a Blacksmith will do to harded steel. Get the metal red hot and then dip it in water? So why does this process soften brass? Im getting ready to start annealing because i have noticed the neck tention is not as constant as it used to be. But I couldn't help but question why it works?
Why does annealing work?
- Thread starter AtownBcat
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Re: Why does annealing work?
<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: AtownBcat</div><div class="ubbcode-body">Almost everyone who anneals their cases finishes the job by dropping it in water.. Isnt this the exact thing that a Blacksmith will do to harded steel. Get the metal red hot and then dip it in water? So why does this process soften brass? Im getting ready to start annealing because i have noticed the neck tention is not as constant as it used to be. But I couldn't help but question why it works? </div></div>
Most of us who do anneal don't drop our brass into water, as it's not needed.
Brass behaves differently than steel. It gets softer when heated up to ~750*.
Your neck tension gets more inconsistent via work hardening because the more you move brass necks in and out, the harder the brass gets and the more it loses its spring back.
Chris
<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: AtownBcat</div><div class="ubbcode-body">Almost everyone who anneals their cases finishes the job by dropping it in water.. Isnt this the exact thing that a Blacksmith will do to harded steel. Get the metal red hot and then dip it in water? So why does this process soften brass? Im getting ready to start annealing because i have noticed the neck tention is not as constant as it used to be. But I couldn't help but question why it works? </div></div>
Most of us who do anneal don't drop our brass into water, as it's not needed.
Brass behaves differently than steel. It gets softer when heated up to ~750*.
Your neck tension gets more inconsistent via work hardening because the more you move brass necks in and out, the harder the brass gets and the more it loses its spring back.
Chris
Re: Why does annealing work?
http://www.6mmbr.com/annealing.html
Here's a good read on brass annealing. Should answer your ?'s.
http://www.6mmbr.com/annealing.html
Here's a good read on brass annealing. Should answer your ?'s.
Re: Why does annealing work?
The primary issue is that brass is a work hardening material while iron alloys are generally precipitation hardening.
The internal crystalline structure of an iron alloy will undergo changes as it's constituent parts heat up and subsequently cool. The temperature that the material is heated to, the duration, the cooling rate, and the normalizing temp and time all make a difference what happens to that iron alloy. There are other things as well, but as you can see the point is that it has a lot going on.
Brass is work hardening. Work hardening happens with repeated plastic deformation, where "plastic" deformation is permanent changes in the shape/geometry through applied stresses.
As you fire/size/load/fire/size/load/fire/size/load the brass cases they work harden. This causes it to have stronger material properties before failure and subsequently the amount of force required to yield the material (in our case, bullet release) is changed. The way to make it repeatable for us (because it varies with each piece of brass) is to anneal it back to the dead soft state each time.
Tom Sarver anneals his 300 Hulk necks every time he fires them when he's shooting for 1k BR records. That's the way to make sure it's repeatable each and every time.
For shooting steel plates and the level of repeatability that most of us are striving for, annealing the necks each time isn't necessary.
I do it at various points for different rifle depending on what I've seen work. My 30-06 gets it every 3-4 firings, the 260 gets it about every 3rd, the 6mm AI that I had was every 7th (very tight neck that required turning so low tension values were per norm). The bolt 223 I usually don't bother, when the necks split, I toss them and move on.
Work hardening also embrittles the material, so when you fire it the high strain rates cause the neck and sometimes shoulders to crack during bullet release. With annealed necks that are properly cared for this becomes a very unusual occurrence.
The primary issue is that brass is a work hardening material while iron alloys are generally precipitation hardening.
The internal crystalline structure of an iron alloy will undergo changes as it's constituent parts heat up and subsequently cool. The temperature that the material is heated to, the duration, the cooling rate, and the normalizing temp and time all make a difference what happens to that iron alloy. There are other things as well, but as you can see the point is that it has a lot going on.
Brass is work hardening. Work hardening happens with repeated plastic deformation, where "plastic" deformation is permanent changes in the shape/geometry through applied stresses.
As you fire/size/load/fire/size/load/fire/size/load the brass cases they work harden. This causes it to have stronger material properties before failure and subsequently the amount of force required to yield the material (in our case, bullet release) is changed. The way to make it repeatable for us (because it varies with each piece of brass) is to anneal it back to the dead soft state each time.
Tom Sarver anneals his 300 Hulk necks every time he fires them when he's shooting for 1k BR records. That's the way to make sure it's repeatable each and every time.
For shooting steel plates and the level of repeatability that most of us are striving for, annealing the necks each time isn't necessary.
I do it at various points for different rifle depending on what I've seen work. My 30-06 gets it every 3-4 firings, the 260 gets it about every 3rd, the 6mm AI that I had was every 7th (very tight neck that required turning so low tension values were per norm). The bolt 223 I usually don't bother, when the necks split, I toss them and move on.
Work hardening also embrittles the material, so when you fire it the high strain rates cause the neck and sometimes shoulders to crack during bullet release. With annealed necks that are properly cared for this becomes a very unusual occurrence.
Re: Why does annealing work?
Tun_x
It depends on how hot you are running them. What name brass may help? I've been running my .308 Hornady brass for about 10 loads and not had to anneal yet. I've seen no split necks. But I'm sure it's getting close. It will also depend on your chamber a tight chamber will not work the brass as much as loose chamber. Also have your dies set-up to do the least amount of forming as required to work in your chamber also cuts down on the work hardening of the brass.
Most of the guys I shoot with say 6-8 loads and they anneal for a .308.
Tun_x
It depends on how hot you are running them. What name brass may help? I've been running my .308 Hornady brass for about 10 loads and not had to anneal yet. I've seen no split necks. But I'm sure it's getting close. It will also depend on your chamber a tight chamber will not work the brass as much as loose chamber. Also have your dies set-up to do the least amount of forming as required to work in your chamber also cuts down on the work hardening of the brass.
Most of the guys I shoot with say 6-8 loads and they anneal for a .308.
Re: Why does annealing work?
<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Tun_x</div><div class="ubbcode-body">Its Winchester brass and I neck size it. The riffle a factory Rem SPS so I would assume its fairly loose. </div></div>
I am running an experiment on this. I have a lot (100 cases) of Win brass that is no on reload cycle 28 without annealing. The load is a stiff 47.8 gr Varget pushing 155 Scenars at a relaxed 2925-2950 fps and a COAL of 2.948. To date, I have not lost a case to primer pockets or to neck cracking (or anything else).
I have nothing against annealing, I'm just running this experiment for fun and personal amusement. I can tell the necks are getting toward the brittle end of things by the way they respond as they get sized in the bushing die. And, no, they are not as accurate as they used to be {That is part of the amusement factor}.
<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Tun_x</div><div class="ubbcode-body">Its Winchester brass and I neck size it. The riffle a factory Rem SPS so I would assume its fairly loose. </div></div>
I am running an experiment on this. I have a lot (100 cases) of Win brass that is no on reload cycle 28 without annealing. The load is a stiff 47.8 gr Varget pushing 155 Scenars at a relaxed 2925-2950 fps and a COAL of 2.948. To date, I have not lost a case to primer pockets or to neck cracking (or anything else).
I have nothing against annealing, I'm just running this experiment for fun and personal amusement. I can tell the necks are getting toward the brittle end of things by the way they respond as they get sized in the bushing die. And, no, they are not as accurate as they used to be {That is part of the amusement factor}.
Re: Why does annealing work?
<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: KHOOKS</div><div class="ubbcode-body">Tun_x
It depends on how hot you are running them....</div></div>
It also matters whether you're full length sizing or neck sizing only.
<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: KHOOKS</div><div class="ubbcode-body">Tun_x
It depends on how hot you are running them....</div></div>
It also matters whether you're full length sizing or neck sizing only.
Re: Why does annealing work?
Thats what I have found also. The case will last fairly well especially if you are using bushing type dies or collet dies. However accuracy does suffer due to neck tension variations as they all don't harden the same. Also as the neck gets unevenly harder resistance to seating the bullet could be a factor .
Uneven hardness of the neck could also cause the bullet to not be released exactly straight into the lands.
Anyway I like to do a partial anneal at about 5 to 10 shots mainly to try and maintain accuracy . 5 shots on my target /varmint brass and 10 on the rest .
Thats what I have found also. The case will last fairly well especially if you are using bushing type dies or collet dies. However accuracy does suffer due to neck tension variations as they all don't harden the same. Also as the neck gets unevenly harder resistance to seating the bullet could be a factor .
Uneven hardness of the neck could also cause the bullet to not be released exactly straight into the lands.
Anyway I like to do a partial anneal at about 5 to 10 shots mainly to try and maintain accuracy . 5 shots on my target /varmint brass and 10 on the rest .
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