Is it worth it to anneal twice - once before and once after resizing?

[NelisB]

I have been annealing my brass with an AMP annealer after every firing. Seeing that most of the hardening of the case neck (at least as per the AMP website) takes place during the resizing process, with an incrementally smaller amount of hardening due to firing, would it be beneficial to anneal again just before priming, charging and bullet seating after resizing?

 

[kelbro]

Doesn't matter as long as you keep your process consistent.

 

[1shot]

Not in my opinion. I re-size, trim if necessary then anneal after every firing.

Lloyd

 

[Longtrain]

I don’t think that’s really necessary. Won’t hurt I guess, but are you chasing your tail? What specific benefit do you feel it provides and have you seen a measurable benefit to double annealing? If so, have at it.

 

[rardoin]

No

 

[NelisB]

I don’t think that’s really necessary. Won’t hurt I guess, but are you chasing your tail? What specific benefit do you feel it provides and have you seen a measurable benefit to double annealing? If so, have at it.

The second annealing would be to get the brass back to the pre work-hardened state. Per the AMP research, annealed brass has a hardness of roughly 98HV if done correctly, once it is sized, the number increases to about 125HV and then to 150HV when fired. Annealing would restore the brass to 98HV, similar to virgin brass and also resetting any inconsistencies in working the brass that I may have introduced in the resizing process. There may also be a fair bit of tail chasing form my side....

 

[Straightshooter1]

The second annealing would be to get the brass back to the pre work-hardened state. Per the AMP research, annealed brass has a hardness of roughly 98HV if done correctly, once it is sized, the number increases to about 125HV and then to 150HV when fired. Annealing would restore the brass to 98HV, similar to virgin brass and also resetting any inconsistencies in working the brass that I may have introduced in the resizing process. There may also be a fair bit of tail chasing form my side....

How about running a test and see if there's any distinguishable difference in the chrono numbers or on paper, huh?

 

[searcher]

It won't hurt - but what, exactly, is the goal in doing so? Properly fitting brass that is annealed every 5 or ten loadings (or every loading) will usually ultimately fail because of primer pockets before the necks give out. So while I agree with your theory- unless you shoot less than full-power loads, it would seem a waste of time to me.

 

[DJSBRS]

Depending on your personal desire, one may want to only resize your fired cases to be .0015 smaller than your chamber. If you require such headspace and body tolerances with your loaded round, I have found many times that not 100% of my annealed brass respond exactly the same and size exactly the same from that batch. I test chamber every full length resized case in my chamber before I start preparing to load for a match. If you are bumping or sizing more than .002 you may not ever feel the difference.

In almost every time I check them for exact fit, I find 3 to 4 cartridge's out of 100 that are slightly tighter than the others. I then re-anneal and full length resize and recheck for proper fit. Almost every time that corrects the problem and I can reload those cases with confidence ( checked for FPS consistency) that I now have the brass exactly the same. On the rare occasion the few pieces of brass does not respond properly to the second reannealing, I trash it. The metal make up on those will not respond along with the others. Life is too short chasing brass issues.

DJ

DJ's Brass Service
205-461-4680
djsbrass.com

 

[Capt. Oblivious]

The second annealing would be to get the brass back to the pre work-hardened state. Per the AMP research, annealed brass has a hardness of roughly 98HV if done correctly, once it is sized, the number increases to about 125HV and then to 150HV when fired. Annealing would restore the brass to 98HV, similar to virgin brass and also resetting any inconsistencies in working the brass that I may have introduced in the resizing process. There may also be a fair bit of tail chasing form my side....

I prefer to aneal before I move brass/size brass and then leave them but this might be an interesting test, guess one will just need to keep an eye on seating force/tension after the second anealing

 

[Ccrider]

The second annealing will effect neck tension.

 

[shoot4fun]

Annealing has a specific function. So does FL sizing.
I believe annealing again after FL sizing will introduce inconsistent neck tension and amount of desired shoulder bump to the point it becomes detrimental.
Note:
DJ says a lot in his post. Even as many thousands of brass as he has annealed there are still outliers.
Even after the "second chance" some brass just isn't going to respond.
Disclaimer:
I am not a metallurgist nor a scientist. I also have not stayed in a Holiday Inn Express in quite a while.

 

[JimSC]

the primary purpose of annealing metal, any metal, is to make it softer for machining and forming purposes. It is interesting to note that the metal used for brass and steel springs are on the opposite side of that spectrum. Those are just facts and can be researched with a minimum of effort, make of them what you will.

edit and back to topic - if I were going to start annealing again I would do it before sizing. Reasoning being that by making the metal softer it increases the range of elastic deformation and eliminates reduces or eliminates springback. I have noticed on some of my cases that are into the double digits that I have had to reduce the neck bushing size by .001 to get the same neck tension. I would not bother with after, on firing springback is inconsequentiaL. Just something to consider

 

[SeabeeKen]

I have been annealing my brass with an AMP annealer after every firing. Seeing that most of the hardening of the case neck (at least as per the AMP website) takes place during the resizing process, with an incrementally smaller amount of hardening due to firing, would it be beneficial to anneal again just before priming, charging and bullet seating after resizing?

Why? Just be consistent

 

[wbm]

Is it worth it to anneal twice - once before and once after resizing?

No.

 

[riflewoman]

Annealing before and after resizing is counterproductive. After the first annealing the brass is in a recrystallized state. Residual cold work is minimal. During the sizing process you do NOT put enough cold work into the brass to have a recrystallization temperature that the AMP can get to without reprogramming. THERE IS A TIME AND TEMPERATURE REQUREMENT. Low cold work higher temperature and longer time. This is also why annealing at low temperatures and “every firing” is also counter productive. This has all been documented here if you search the archive and is well known in metallurgy.

 

[Artisan]

If this is your potion, please by all means, keep doing what you works for you. Even if it is in thought alone, the mind is a powerful motivator and if you happen to think, even just a small amount, it will help, continue onward.

 

[Dusty Stevens]

Why relax it after you size it? It wont relax the same on each piece. Anneal then size

 

[bozo699]

The second annealing will effect neck tension.

So will the first.
Wayne

 

[LVLAaron]

Doesn't matter as long as you keep your process consistent.

Exactly.