What frequency of Annealing for best case life and consisitent accuracy?

[jimbires]

Don , proper annealing takes time and temp . you can anneal at lower temps , BUT you must keep the heat on for a longer amount of time . the problem here is the longer time allows the heat to travel the case body softening the case head , this is no good . I try to get my brass up to temp , and out of the heat quickly , to avoid heat travel . I don't cool with water , I don't think this adds anything to the process except for getting wet brass .

your example of 680*F for 1.7 seconds ;
I'm guessing would accomplish little or nothing . you have lowered the temp , and shortened the dwell time in the heat .

 

[Beneviolence]

Annealing a case neck only requires the brass be brought to 'the correct' temperature and held there for the appropriate amount of time. It's the temperature reduction process that has the more profound effect when seeking consistency in resetting the alloy's natural molecular structure. Much as work-hardening has a more profound/immediate effect on neck tension.

At the risk of being blunt, that's not how it works. Annealing is a three step process that requires the cold worked material at sufficient temperature for a certain amount of time; it does not require a specific cooling rate. Word hardening the material influences neck tension because when you go to size it back to the pre-fired size that your bushing is set to, it now has a higher yield strength and associated elastic strain region and will spring back. This decreases your neck tension as it becomes more and more work hardened.

 

[rcoody]

lots of misguided souls on this thread. everything from red hot and quenching like tempering a blade to cook them at below brass annealing temps for a long time. where do people get this information?

call the AMP guys if you want the definitive answer on annealing.

 

[Rich Coyle]

Someone mentioned no annealing is preferable to the "wrong" annealing.

Since I do wildcats that move necks out to where the shoulder is, I discovered any annealing reduces splits.

 

[Mikecr]

it now has a higher yield strength and associated elastic strain region and will spring back. This decreases your neck tension as it becomes more and more work hardened.

Work hardening of neck brass does not decrease neck tension.
Neck tension/grip IS spring back, against a chosen bearing area. The stronger the spring back against given area, the stronger the tension.
If you had a desire to remove all tension, you would achieve this with a full anneal, and most would consider that brass killed. What we do is process annealing, which is below full annealing. ~850degF for ~10sec will do that job.

An advantage to frequent consistent process annealing is that you're lowering tension, which lowers tension variance. But this advantage only exists when a developed load likes it. No guarantee there. In fact many cartridges shine with loads requiring higher starting pressures. For this reason, I do not anneal frequently, but manage tension for best results otherwise(through minimal sizing, and careful correlation of seating forces).
An advantage for those of us who dip is that we can do a deep body process anneal. This allows for wildcat full case forming within a couple firings.

 

[Beneviolence]

Work hardening of neck brass does not decrease neck tension.
Neck tension/grip IS spring back, against a chosen bearing area. The stronger the spring back against given area, the stronger the tension.
If you had a desire to remove all tension, you would achieve this with a full anneal, and most would consider that brass killed. What we do is process annealing, which is below full annealing. ~850degF for ~10sec will do that job.

An advantage to frequent consistent process annealing is that you're lowering tension, which lowers tension variance. But this advantage only exists when a developed load likes it. No guarantee there. In fact many cartridges shine with loads requiring higher starting pressures. For this reason, I do not anneal frequently, but manage tension for best results otherwise(through minimal sizing, and careful correlation of seating forces).
An advantage for those of us who dip is that we can do a deep body process anneal. This allows for wildcat full case forming within a couple firings.

My statement regarding the work hardening reducing neck tension was intended to say that if you have the same starting neck diameter for an annealed/fresh brass versus a work hardened (multiple fire/size) and neck size them with the same size bushing, the work hardened brass will spring back more and have a larger ID/OD after sizing than an annealed. If I understand what you're saying in the rest of your post correctly, I agree with it.

 

[Mikecr]

Ideal sizing would squeeze fired necks to 2thou under cal for a length not exceeding seated bullet bearing. The neck having normal hardness would spring back ~1/2thou from this to 1.5thou under cal. Then we would pre-seat expand necks to cal, and the necks should spring back from this to 1thou under cal, ready for bullet seating.
Correctly process annealed necks give us this, and if we don't work the necks a lot to squeeze them 2thou under cal from fired, they will not harden so much as to need frequent annealing. They will get a little harder by the time brass is fire formed, and then the change is less with further cycles. I load develop with this.

With sizing described from chamber necks no bigger than 2thou over loaded neck ODs, and monitoring of my seating forces, it turns out that I should re-anneal at around 10 reload cycles. With my tight necks(~1thou over loaded), and fitted necks, annealing beyond initial is never needed again.

Some folks do not establish this sizing plan, with many going far into excess, or cutting corners(like not pre-seat expanding). Annealing may help them, or hurt them, but I don't see it as addressing a root cause of their woes. Where it is needed, no way around it, or even chosen as frequent, the annealing needs to be right & very consistent.
To be sure of this, I dip anneal. No way to get that wrong.

 

[ChrisInKY]

when you go to size it back to the pre-fired size that your bushing is set to, it now has a higher yield strength and associated elastic strain region and will spring back

And this is why I partially neck size and anneal each case twice when re-loading for precision.

I think what I'm failing to get across (in words) is that if you don't let the brass completely relax (which only time is going to take care of effectively) you're introducing inconsistencies. I don't know how much time people are willing to spend on these endeavors, but I'm beginning to realize most rush between various stages in their re-loading process.

It takes me 4 days to re-load for precision start-to-finish. The vast majority of that time is an act of patience. What I get out of it is the reduction of as many variables as possible. My ES/SDs are as low as I can get them. They're far lower than the average re-loader's and that's good enough for me.

For contrast ... I can crank out 500 rounds of SAAMI spec ammunition in an hour or so on my Dillon. I run those cases through my annealer only to keep the necks from splitting. They go through once and they're into the case feeder as soon as they've cooled to room temp. Fine for varminting or plinking ... not good enough for 500+ meters.

-Cheers

 

[Buckskinner]

I miss this string!

 

[Chuck32571]

I have periodically annealed brass for a tactical competition rifle every 3-4 firings. Now I am starting to delve into LR/ELR shooting with a 7mm Remington Magnum, and soon a 300 Winchester Magnum. Based on your experience, what would your recommendation be for intervals between annealing brass for these cartridges. Thanks.

I own a Perfect Annealing Machine and anneal after every firing. The unit has settings for almost every cartridge manufacturer and makes it easy to anneal a batch in minutes. An added bonus is if you anneal prior to resizing it makes the resizing process smother with no expander ball hang ups.