Annealing?

[1Shirt]

Because I have had a good qty of brass on hand for most of my rifles, I haven't annealed any in a number of years. When the necks started to split I just pitched the batch. However, am now shooting a fair amound of K-Hornet, and after fire forming, am starting to get neck splits after about 3 rounds, so tonight I broke down and annealed a hundred of the little fellers.
Would be interested in any other hornet/K-hornet shooters experiance with case life and if/when (after X number of firings) they anneal. Back when 06 was scarce for me I used to anneal after every 5 loads, and had some LC-62 match that had been loaded well over 20, and maybe 25 times.

Thanks in advance to all who answer this thread.
1Shirt :coffeecom

[Buckshot]

............No experience with the K-Hornet but annealing most others I do. Offhand I know I have have several 20 orund batches of LC-45, '-06 brass with well over 30 firings apiece. These get annealed about every 6-7 loadings, or when you can tell they just aren't sizing right anymore. Thier longevity due no doubt to a good tight chamber in the 03-A1, plus use of a Lee collet die.

I have several 20 round batches of 577-450 M-E with well over 30 firings each. These get annealed every 3 firings and I watch them like a hawk, due ot their expense. Probably most troublesome for me is 7x57 and 7.65x53. I keep brass detailed to an exclusive rifle. However, I have a couple 7mm military's that you can about drop a 30 cal bullet through one of their fired casenecks.

Seems as even judicious annealling may only give another 4-5 firings (maybe 10-12 total) before they're scrap. Lots of expansion and re-szing going on there. I like the necks of annealed cases to 'just' drag on the collet spindle when withdrawing the case.

................Buckshot

[felix]

I use the military method (a'la' Olin), and that is to rotate the case about a very fine needle like continuous flame. A full anneal is done when the brass has changed to the proverbial military case color down through the neck. In the situation where there is a rim on the case for headspacing, I don't allow the color change go past (or much past in reality) the boolit seating depth. I watch for the color change by knowing how red the neck gets when doing the job in almost pitch black conditions. If the case material is thin, like for a Hornet, I allow the flame to hit only the open edge of the neck, because that material is terribly thin in terms of the heat applied. If the cases are thin OR short, I drop the heated case into a bucket of water for rapid cooling. If the cases are thick, and the case crack from firing the gun goes through the first half of the case, then I drop the case onto the ground. Annealing is a function of heat amount which is temperature and time in combination. A military anneal will start the case life over as if it had never been fired in the first place. If the primer pockets become too loose too quickly, then you annealed the case too much! Remember that for the next anneal a different batch of cases for that same gun. Either cut the heat amount, or the time in the flame. ... felix

[1Shirt]

Good and interesting responses. I agree with Buckshot on just a bit of drag on the withdrawl of bottle neck cases. I deprime cases, stand them in H2O up to the level I want to anneal, hit them for X time count with flame (Just starts turning color), and tip them into the water with a long nail. Can almost judge effectivness as well from the sizzle at they hit the water, as I can from the color. This seems to work well for me. Thanks for the responses.
1shirt :coffee:

[versifier]

I know that air cooling works great for annealing steel, while quenching in water or oil at different tempertures hardens (tempers) it. :shock: Doesn't water quenching hot cases (not just sitting them in water to limit heat transfer) harden the brass? While not a metalurgist, and, admittedly, most of my machining experience is with steel, I would think that it would be logical to assume too rapid cooling can only increase the brittleness of brass just as working it too much will do. :holysheep Who can educate me here, please? :?:

[FUDD]

Just let it sit in the room and come to room temperature after the heat. That is annealing.

[versifier]

FUDD, That was my understanding also. My concern is that tipping over the hot cases into the water is a case of three steps forward two steps back. It's just that sometimes what seems to be a logical assumption doesn't hold true in the real world, and I am wondering to what degree the brass is rehardened by the quenching. Is the difference significant, or is it meerly measurable but of no noticable practical effect?

[waksupi]

Just a thought or two. I've done quite a bit of blacksmithing over the years. For annealing steel, I would heat it to cherry red, then bury the piece in the bed of coal in the forge, and let it cool there overnight, for the maximum softness. On harder blister steel, I would use powdered lime, and immediately bury the piece in this, allowing it to cool. I wonder if maybe it would be worth while, assuming one could hold the brass in his fingers to heat it, immediately sticking the case neck into some lime?

[beagle]

Been shooting a bunch of Hornet lately. Started out with a bunch of fairly old brass and annealed it as I was afraid of neck cracks also.

I haven't had the first split or neck crack after 5-6 firings.

The Hornet does seem to expand primer pockets quite readily if you hot rod the loads. After these are gone, I have 500 rounds of new stuff waiting in the wings that I'll treat more tenderly.

I'd aneal and neck size only./beagle

[felix]

Heat makes things soft, right? If you want it really, really soft, melt it! Can't get it any softer, right? OK, somewhere in between would be about correct. Thus, we are talking time as well as temperature, but only past a certain threshold which is alloy (copper or steel) dependent. If we are just barely past that temp threshold, which is calculated in a lab, then it takes a lot of time for all of the elements within the alloy to move into an equilibrium state. The hotter the metal goes past the equilibrium point, the less time it takes to do the SAME job of moving the microscopics into an equilibrium state. The tricky part is what the material is made of and finding out the various equilibrium states past the first one, if indeed there are any. Going to the next level will make the material softer. Stopping the cooling is stopping the softening, and that is all there is to it. ... felix

[StarMetal]

beagle,

When I bought my Hornet back when I lived in Ohio I bought 100 rounds of brass for it whtat has be repeatly reloaded over and over many many times and with both cast and hot jacketed loads. I haven't lost a piece of brass yet. Now I use the Lee neck sizing collet die and my rifle is a CZ which may hae alot to do it because I'll bet it has a tight chamber.

Joe

[KYCaster]

I know that air cooling works great for annealing steel, while quenching in water or oil at different tempertures hardens (tempers) it. :shock: Doesn't water quenching hot cases (not just sitting them in water to limit heat transfer) harden the brass? While not a metalurgist, and, admittedly, most of my machining experience is with steel, I would think that it would be logical to assume too rapid cooling can only increase the brittleness of brass just as working it too much will do. :holysheep Who can educate me here, please? :?:


There you guys go, trying to use LOGIC again. You know how that always gets you in trouble.
Unlike steel, copper alloys get softer with a faster quench. Heat to dull red and water quench, works every time.

Jerry

[David R]

In MY opinion, quenching is the way to go. Non ferrous (did I speel it right?) metals like aluminum and copper soften from quenching. Lead and Steel harden, depending on the alloy and the quench.

David

[versifier]

Thank you guys. That clears up the mystery. Copper and aluminum alloys soften. What other metals is this true for? So, would allowing brass to return to room temperture without quenching harden it? :coffeecom

[Buckshot]

.............The way you harden brass is by working it. Heat softens it. I heat it with the neck in a propane flame until the neck just starts to redden and the heat line has moved down just past the shoulder. Then they get dropped into water.

............Buckshot

[357tex]

I think I heard of annealing by dipping the case mouth into the casting pot and then dropping into water.
Am I crazy or do I have a poor memory?

[wmitty]

A method which has worked well for me has been to hold the case between thumb and index & middle fingers of left hand. By rotating the case while playing propane flame on the neck, a case can be annealed and dropped in water about every seven or eight seconds. The heat travels thru the brass to your fingers and the case head very fast; prevention of over-heating (softening) of the case head is achieved by the the signal your brain sends to your fingers telling them to LET GO NOW. The water quench instantly stops any heating of the case head.

[David R]

Yes I have heard of holding the necks in molten lead until it burns your fingers, then quench. Never tried it my self. I think a gunsmith told me that one.

David

[Haywire Haywood]

Veral Smith just told me how he anneals gas checks and it seems to work. He said to get a pipe nipple, fill with GCs and then cap both ends (or rather, cap one end, fill, and then cap the other end). You then drop this into your >700F melt and let it stay for at least 30 minutes. Pluck it out, let it air cool, and you have annealed GCs. No water dropping. I think the cast iron pipe nipple might protest to going from 750 to 70 that fast.

Ian

[1Shirt]

I annealed a batch of 22 and a batch of 30 cal gas checks, and frankly could not tell the difference in sizing so felt it was a waste of time.
1Shirt

[StarMetal]

I've annealed gaschecks and found a MAJOR difference in sizing. Wonder why you didn't?

Joe

[Bass Ackward]

If you get your checks from a sourse that moves them pretty quickly, then there is a good chance that you might not see much difference. Especially if you are holding velocities to 2000 fps or less. And if you are doing draconian sizing. Another posibility is that the anneal process that was tried was unsuccessful.

This same "freshness" quality is what I use for brass too. Brass will harden just sitting there. If you buy brass from a place that doesn't move much, you can and probably will have troubles sooner than fresh brass. I got several boxes of 06 brass given to me from a gentleman that died ten years ago and every attempt to size one, splits the neck in a perfect line down into the shoulder. The brass is Remington, Winchester and Federal. I can anneal the necks, but what worries me is the heads. So the brass has sat now for a couple of years.

[BeeMan]

There you guys go, trying to use LOGIC again. You know how that always gets you in trouble.
Unlike steel, copper alloys get softer with a faster quench. Heat to dull red and water quench, works every time.

Jerry

Jerry is close, as I understand the subject. Cartridge brass is 70/30 copper/zinc and is softened by heating above a threshold. Iron alloys are fundamentally different in thermal properties. Some sources make a distinction between stress relieving and true annealing of cartridge brass. The difference seems to be in the degree of grain structure change at various temperatures and times. I don't think quench speed makes a difference with copper alloys, though it is important with steels.

Occasionally someone will suggest an alcohol lamp for a lower flame temperature when anneal brass. The same result can be achieved with propane by a shorter exposure time and good position control within the flame proper. Start with too little total heat input and work up. You can always re-heat if needed, but once over softened the case is scrap. Heat sink the case head, use a higher rate of heat input, or hold the base in your fingers; whatever works to confine softening to the neck and shoulder area. Consistency is key, which we seek to apply to other parts of our fascinating hobby.

Brass hardens by working and apparently also with time as BA mentioned. This can lead to cracks in loaded round case necks, but I suspect stress and time combine to create the crack. I've never found a good answer other than to shoot the loaded rounds rather than let them sit for long times.

I use a propane torch, hold the brass with Lee case trimmer turned by power screwdriver, and drop into water for convenience. The water has no noticeable effect on final softness after the temperature change threshold in the brass is reached.

Varmint Al has a good discussion of case prep including annealing at http://www.varmintal.com/arelo.htm

Also, not all steels harden by heating and quenching. If I remember right, some alloys are preciptitation hardened.

I'm not a metallurgist, just learning material properties as I go. :roll:

BeeMan

[versifier]

OK so far. Maybe I'm getting into the realm of hijacking, but I got to thinking about copper alloys and the next question that occurred to me is: How were the edges of bronze weapons hardened? By working them cold on the anvil?

[StarMetal]

versifier

Most non-ferrous metals can only be hardened by "work hardening", hammering, rolling, bending. But they can be softened by "annealing" which is heating to a red heat and then cooling quickly.

Joe

[felix]

Rate of cooling has nothing to do with copper-zinc annealing, Joe, unless you want to stop the annealing from going further. Not like lead-antimony. ... felix

[StarMetal]

Felix,

The cooling was only mentioned into context that it's the exact opposite of Ferrous metals, that's all. You are, however, correct about the time period.

Joe

[Newtire]

Way I did some annealing awhile back on a bunch of '06 brass was to set the cases in a big cake pan (I have my own stash of those kinds of things in the garage-NOT MOMMA's), filling it with water and then playing the propane torch on them to the same degree of redness one at a time & then tipping them over one at a time. Sure don't take that long & this way, they say, the head doesn't get hot. I'd be real careful with brass as short as Hornet brass. They all worked fine and were definitely softer. All looked kinda uniform darkness down to just the shoulder. Used them with some full power loads with no problems.

[versifier]

Sorry I missed a few days. Went deer hunting up in the Noth Woods for the opening of rifle season. Lots of deer, tons of partridges, missed deer, forgot shotgun, great trip anyway. I want to thank Joe, Felix, BeeMan, Jerry, David, Oneshot, Buckshot, and Fudd for furthering my education. I have cut & pasted most of this thread into a .doc where I can refer to it. [smilie=w:

[pireaux059]

:coffeecom Just wanted to thank yall for the very informative post annealing has been kind of a mystery for me this should help JD :veryconfu

[Haywire Haywood]

Yes, I also was puzzled about hardening boolits by water quenching and softening copper by the same process. Thanks for the education.

Ian