Case annealing, extend life or no?

[shibumiseeker]

Starting a new thread...

We've had some discussions of annealing, and there are good reasons to do it, but who has actual empirical data on whether it increases case life?

Since I do a lot of these types of tests, I'll be conducting one of my own here maybe next week when I get the time, but anyone else?

 

[slow1911s]

Good article on the subject - The Art and Science of Annealing within AccurateShooter.com

 

[kludge]

^That^ article is the best one I've found.

Personal empirical data: while working on/validating my annealing process for my wildcat, I grabbed some .308 brass, probably thrice fired, and necked it up to 35 caliber.

The un-annealed necks split easily. The annealed .308 necks expanded to .35 caliber fine.

New brass (I don't have any new .308 brass I used new .25 WSSM brass to form my wildcats) is annealed at the factory and I necked them up to 30 caliber then 35 caliber and no necks split. Once they were at full diameter I annealed them again. A few of the .35 WSSM cases now have been resized three times and no split necks so far. I think I will anneal them after every third firing. 3-5 seems to be the going number.

Whatever you do DON'T do this:

YouTube - How I Anneal Brass

Cherry red RUINS the brass (too soft), and is a good way to get a case stuck in the chamber. Cherry red removes all the hardness from the brass and the brass doesn't spring back when the gun fired (both the chamber and the brass expand during firing and both should spring back). If the chamber springs back to it's original size but the brass doesn't you're in trouble. Actually the brass will spring back to within a thousandth of an inch or two of it's original size, and the bullet will be a slip fit, but you should still have a thousandth or two of clearance between the brass and the chamber. If you soften the brass too much it will expand to fill the expanded chamber (as does correctly annealed brass) but it won't spring back, and when the chamber contracts you now have stuck brass.

In an overpressure situation (even with correctly annealed brass) the chamber expands more than the brass can spring back and the case will be stuck in the chamber. If you're lucky you'll still be able to open the bolt.

Anyhoo... You want a light blue color. There are some temperature crayons available from places like McMaster that will help you get the right temperature. Hornady makes a rather expensive kit too.

Here's how I do it:

YouTube - Annealing Brass

@3:25 shows the right color, a dull blue.

 

[CountryBoy19]

Cherry red RUINS the brass (too soft)

Oh man, I couldn't even finish watching that video.

The guy mentioned that when you get the brass glowing hot, and then quench it, it tempers the brass, so it's rehardening the brass to the perfect amount.

That is 100% completely phony baloney. That is true with steel and certain other metals/alloys, but brass alloys do not and cannot be hardened at all from quenching a red-hot specimen. Getting it red-hot the quenching gives you "dead-soft" brass, which means that is as soft as you can possible get brass. As a matter of fact, because of this, there is absolutely no difference between brass that was air-cooled or water quenched. The only difference is that the case head doesn't get as hot when you quench it. But that point doesn't really matter because if you're annealing properly, the case head isn't getting near the temps required to anneal it.

 

[slow1911s]

Might you do the cherry red heating if you were fire-forming your brass? And then, after fire forming, anneal back to appropriate hardness? (just throwing that out there - after the explanations given, that seems like it might be the only reason to do it, but it's a SWAG on my part)

 

[kludge]

No. If I were fireforming brass...

A) I would be using new brass, or
B) If I wasn't sure it was once fired, I would anneal beforehand.

Annealing after fireforming can't hurt.

 

[shibumiseeker]

Good article on the subject - The Art and Science of Annealing within AccurateShooter.com

It is indeed a great article on how to anneal, and I think most of us would agree that having case mouth tension being constant is one of the bigger variables in precision shooting, but it really doesn't answer the question: Just how much longer does annealing (assuming proper annealing) make a case last?

I had a medium loaded case on a .22-250 last some 76 loadings with no annealing and the final failure mode was a neck split, would the process have extended the life considerably or a little bit? If we anneal to increase case life, in general how much more case life could we expect?

My expectation is that case life for a light loading would not benefit as much as case life for a hot load, but how much? Who's done side by side studies?

 

[CountryBoy19]

Might you do the cherry red heating if you were fire-forming your brass? And then, after fire forming, anneal back to appropriate hardness? (just throwing that out there - after the explanations given, that seems like it might be the only reason to do it, but it's a SWAG on my part)

Well... when you heat it up cherry red there is more going on than just making it dead soft. You're burning a lot of zinc out of the brass alloy. This means that you're left with mostly copper, and copper alone doesn't work harden as much as brass. So if you did this to fireform, you would be changing the alloy of your brass around the neck. Also, it will take much more than fireforming to get the copper back up to the necessary hardness.

It's best to just properly anneal the brass so as not to change the alloy or soften it too much...

 

[Yeah]

I've fireformed thousands and thousands and thousands of rounds into AI versions and have never annealed. I typically lose the primer pockets before running into neck problems

 

[sloughfoot]

I've fireformed thousands and thousands and thousands of rounds into AI versions and have never annealed. I typically lose the primer pockets before running into neck problems

This +1. Annealing rifle brass is a total waste of time. And butane.

 

[Litlratt]

Apparently, it depends on the brass.
I have some Winchester 243 WSSM brass that was neck splitting on the first firing. Annealed the cases and resolved the issue.
I've never had a need to anneal other than that.

 

[sloughfoot]

Maybe it depends on the brass, I suspect maybe the sizing die too? Is there a "hard" spot when the brass comes out when resizing? Some die designs ae pretty tough on the neck with rapid transitions.

I should probably qualify my statement that the calibers I reload for are .223, .243, .308, .270, 30.06, .260, 6mm AR. Mostly all common calibers. I don't have the need to anneal for any of these.

YouTube - Neil Young - Rockin' In The Free World

 

[sloughfoot]

Neil Young was not my intended link, but now that it is in the post, with people "sleeping in their shoes" maybe it puts the annealing debate into perspective. I don't think I will delete it. It is kind of apropo in some way.. Of course, the Mods may think different..

I like to listen to it with stereo headphones.

 

[CountryBoy19]

This +1. Annealing rifle brass is a total waste of time. And butane.

I think it is highly dependent upon many factors.

Sure, with AR brass where you'll get case-head seperations eventually it may be a waste of time to anneal.

But if you neck-size only for a bolt gun it can help a lot. There was a guy over on the hide that got 157 reloads out of the same piece of brass. He neck sized only, and he annealed every X number of rounds.

Annealing also helps when forming certain cartridges. Just because you've been able to fireform 1 cartridge without needing to anneal doesn't mean you can do them all.

If annealing was a complete waste of time then they wouldn't anneal factory brass after they finished making it.

 

[fireball168]

Like most things, annealing is only one piece of the puzzle - it isn't the "answer" very often in and of itself.

If the chamber dimensions, brass dimensions, and reloading die dimensions all closely match - it isn't difficult at all to see the benefits of annealing (and to know exactly when you need to do it).

Unfortunately, oversized chambers are as common as undersized brass and reloading dies are all over the place.

If you fix one of the problems above, you'll notice a difference in performance and brass life, if you fix two the difference is clear as day - when all three match, you've got something to keep.

If you've got a factory rifle that shoots, but the brass is coming out of the chamber "improved" because of the loose dimensions, have a custom die made or have your existing sizing die modified so you aren't sizing it any more than necessary. Off the shelf neck dies are rarely an acceptable "fix".

If you are rebarrelling, get a copy of the reamer print. Send it to your preferred die manufacturer with a piece of your intended brass and have them mark it up on how much sizing the brass will receive with their dies (they generally won't give you internal dimensions of their off the shelf dies).

If it is more sizing than you want, have custom dies made off that reamer print.


Annealing in and of itself "masks" many unresolved chamber, reloading die and brass problems.

 

[Clay]

I dont do any reloading, but I do work in the metals industry, specifically aluminum which is similar to brass for the most part.

We work harden the alum. as we process it. Eventually we start to get edge cracks if we dont address them, and this will eventually cause us issues. We either trim the edges, but generally we do an anneal in the middle of our processes to soften the metal back up so we can avoid any edge cracking problems. I believe this would have the same effect on brass cases since you are working that brass when its fired and loaded, making it harder over time.

 

[shibumiseeker]

Like most things, annealing is only one piece of the puzzle - it isn't the "answer" very often in and of itself.

If the chamber dimensions, brass dimensions, and reloading die dimensions all closely match - it isn't difficult at all to see the benefits of annealing (and to know exactly when you need to do it).

...
Annealing in and of itself "masks" many unresolved chamber, reloading die and brass problems.

Thanks for a very informative and knowledgeable post!

I think what I'm getting here is that if there is empirical data out there on just how much case life is extended it's not been widely distributed. It sounds like a body of data that needs to be worked on.

 

[CountryBoy19]

Like most things, annealing is only one piece of the puzzle - it isn't the "answer" very often in and of itself.

If the chamber dimensions, brass dimensions, and reloading die dimensions all closely match - it isn't difficult at all to see the benefits of annealing (and to know exactly when you need to do it).

Unfortunately, oversized chambers are as common as undersized brass and reloading dies are all over the place.

If you fix one of the problems above, you'll notice a difference in performance and brass life, if you fix two the difference is clear as day - when all three match, you've got something to keep.

If you've got a factory rifle that shoots, but the brass is coming out of the chamber "improved" because of the loose dimensions, have a custom die made or have your existing sizing die modified so you aren't sizing it any more than necessary. Off the shelf neck dies are rarely an acceptable "fix".

If you are rebarrelling, get a copy of the reamer print. Send it to your preferred die manufacturer with a piece of your intended brass and have them mark it up on how much sizing the brass will receive with their dies (they generally won't give you internal dimensions of their off the shelf dies).

If it is more sizing than you want, have custom dies made off that reamer print.


Annealing in and of itself "masks" many unresolved chamber, reloading die and brass problems.

Very good post.

Yes, it is true that most problems you encounter that can be "masked" by annealing can be solved other ways.

However, sometimes it's just not possible to have all your rifles/dies/etc to match perfectly. For example, if you have 7 different guns that shoot the same cartridge are you going to have 7 different custom dies made? Most people just can't afford that. So annealing becomes a cheap, easy fix to extend brass life in the situations where it would stress crack sooner.

 

[Yeah]

Just because you've been able to fireform 1 cartridge without needing to anneal doesn't mean you can do them all.

Which ones do you think I've not done? Better name an obscure one....

 

[CountryBoy19]

Which ones do you think I've not done? Better name an obscure one....

Let me be the first to say that making AI cases doesn't really change much on the neck shoulder. Try something that doubles your bullet diameter, or radically changes the shoulder. Then tell me that you have fireformed thousands without needing to anneal. I'll bet you have a different opinion of it. I've formed .219 zipper cases from 25-35 cases and I can tell you from experience that if you don't anneal after forming, then by the 2nd reload you have about 40% cracked necks, and by the 4th reload 90% of necks are cracked. Annealing makes the brass last much longer (haven't reached the end of life on an annealed case yet).

But that is because I'm radically changing the neck/shoulder area.