Easy case annealing

[JLA]

I have been meaning to do a thread on a simple means of case annealing for some time now. Finally got around to it.

Tools required:

A propane torch
A Lee case length guage & lock ring for the caliber being annealed
A Lee trimmer & drill stud
A Hi speed hand drill

I included the case length guage and trimmer not only because you have to buy them to get the lock ring and drill stud, but also because I trim and anneal at the same time.

I did 50 .308 cases here and it took me about 30 minutes start to finish. So its relatively quick and simple.

so here we go...

[JLA]

First, get everything set up.

I like to sit the torch in the floor at my feet just off to the side of my chair.

Load the brass case into the drill stud and lock it down. Rotate the case at full speed in the drill and stick the neck into the flame. It just takes a couple seconds to anneal so you gotta pay close attention. Watch the flame coming off the casemouth and pull the case when the flame turns orange (approxiamtely 3-4 seconds). I then insert the caselength guage and trimmer and trim them to minimum spec. After trimming i unlock them from the drill stud and set them aside. Dont worry they are suprisingly cool for just having spent 4 seconds in a 2500 degree flame..

[JLA]

Ill admit there is somewhat of an art to this method in that you dont have a thermometer, or an jig to automatically reproduce the same results time after time, or anything like that. So ill show you guys the 'orange flag' again. The 'Orange Flag' tells you its done annealing and any longer and you will scorch the case and make the neck brittle, thus ruining it.

Note the orange flame coming just off the casemouth. it will only do this just as the case starts to glow red and it is the exact moment you want to remove the case from the flame.

[JLA]

It takes just a little practice to get the hang of it and once you do your cases will last longer and look just like factory annealed brass..

[JLA]

Oh yeah. and it helps to have a helper when you reload.

This little guy is always pulling the press handle for me and helping me sort cases.

[American Leader]

Way to go JLA! However, I read an article about this that stated any exposure to temp of 950 degrees or over for any amount of time made the brass too soft and dangerous. Are you sure you're hitting 2500 degrees? Here's the article where I read this, maybe I misunderstood.

http://www.lasc.us/CartridgeCaseAnnealing.htm

[Bill DeShivs]

Getting the case hotter won't make it brittle, only softer.

[JLA]

I turn them in the flame just until the mouth begins to turn cherry then remove it. If you watch an induction annealing process or a commercial furnace conveyor like the factories use they all are using different methods to get the same end result. The case mouth just starts to glow when the case is pulled away from the heat and set aside to cool or water quenched.

Im NOT heating the cases to 2500 degrees thats just my guess at the approximate temp of the map gas flame. Which is a tad low. Its actually alot closer to 4000 degrees farenheit according to wiki.

The cases are prolly getting to somewhere between 200 and 300 degrees below the shoulder as I can handle them long enough to take them out of the lock stud after annealing. The mouth is the only part that even comes close to glowing red. Which is exactly what you want. Some folks quench with water, I only quench small cases like .223s. The bigger cases I air cool.

[JLA]

Originally Posted by Bill DeShivs

Getting the case hotter won't make it brittle, only softer.

Correct you are Bill, I 'wiki'd' it to confirm. I find the end result is the same. If I burn a case they will split out on the next firing. I first started trying my hand at annealing with .30-06 cases. I scorched them big time. I held them to the heat til the entire neck and shoulder were cherry red. 40 out of the 50 split from mid case body to mouth on the next firing. I was disappointed to say the least. It was Nosler custom brass..

[LDBennett]

JLA:

Why not use the temperature sensitive paints to assure you never get above the temperature that hurts the brass. It is said to be a narrow band of temperature of less than about 50 degrees or so (?) that is "correct" for proper annealing without ruining the brass. See the article below from http://www.6mmbr.com/annealing.html:

The problem with winging the temperature is that a subtle grain change occurs at higher temps that reduced the strength of the brass significantly according to the article (??).

LDBennett

Optimal Case Temperatures for Successful Annealing

Brass is an excellent conductor of heat. A flame applied at any point on a case for a short time will cause the rest of the case to heat very quickly. There are several temperatures at which brass is affected. Also, the time the brass remains at a given temperature will have an effect. Brass which has been "work hardened" (sometimes referred to as "cold worked") is unaffected by temperatures (Fahrenheit) up to 482 degrees (F) regardless of the time it is left at this temperature. At about 495 degrees (F) some changes in grain structure begins to occur, although the brass remains about as hard as before--it would take a laboratory analysis to see the changes that take place at this temperature.

The trick is to heat the neck just to the point where the grain structure becomes sufficiently large enough to give the case a springy property, leaving the body changed but little, and the head of the case virtually unchanged.

If cases are heated to about 600 degrees (F) for one hour, they will be thoroughly annealed--head and body included. That is, they will be ruined. (For a temperature comparison, pure lead melts at 621.3 degrees F).

The critical time and temperature at which the grain structure reforms into something suitable for case necks is 662 degrees (F) for some 15 minutes. A higher temperature, say from 750 to 800 degrees, will do the same job in a few seconds. If brass is allowed to reach temperatures higher than this (regardless of the time), it will be made irretrievably and irrevocably too soft.

Brass will begin to glow a faint orange at about 950 degrees (F). Even if the heating is stopped at a couple of hundred degrees below this temperature, the damage has been done--it will be too soft. From this discussion we can see that there are four considerations concerning time and temperature:

1. Due to conduction, the amount of heat necessary to sufficiently anneal the case neck is great enough to ruin the rest of the case.

2. If the case necks are exposed to heat for a sufficient period of time, a lower temperature can be used.

3. The longer the case necks are exposed to heat, the greater the possibility that too much heat will be conducted into the body and head, thereby ruining the cases.

4. The higher the temperature, the less time the case necks will be exposed to heat, and there will be insufficient time for heat to be conducted into the body and head.

You can see that there are a couple of Catch-22s involved in this annealing business. On the one hand, the brass conducts heat quite rapidly, and a fairly high temperature with sufficient time must be attained to do the job. On the other hand, too much time cancels the effect, and we will be left with a case that is too soft and not suitable for anything but scrap. Obviously, there must be a solution; otherwise, not even the cartridge manufacturers could do it right.

[JLA]

Tempilaq would be a good thing to use if youre just starting out. But once you get a feel for it and you establish a routine and know what you are lookin for it isnt necessary IMO. I have been annealing this way for a couple years now and havnet screwed any cases up since that first batch of .30-06s, well and the first time i did .223s. Thats when i decided .223s and other small cases need quenching..

[garydude]

Excellent post Josh! Thanks for helping the masses understand annealing.

BTW, your little one is as cute as they come.

[Marlin T]

JLA, that last picture is the best

[jack404]

JLA, thanks for posting this .. i'm gonna rip it off and PDF it and put it in the reloading section for all the want to reload folks

cheers and well done eh

[gdmoody]

Here are a couple of silly questions and ones I should probably know the answer to . . . . but . . . what is the benefit of annealing the case neck? And is only the neck that gets annealed?

[Alpo]

Every time brass is expanded (like from being fired) and contracted (like from being resized) it "work hardens". The harder it is, the less it likes to expand and contract. Hard equates to "brittle", and instead of expanding, it ruptures.

Annealing is the process of using heat to soften the brass, which allows it to expand and contract again.

Let's say, just for argument's sake, that you take a piece of factory-new brass and load it six times. The seventh time you resize it, it cracks. It had "work-hardened" too much to allow it to squeeze back down.

But if you had annealed it, after the fourth firing, and then annealed it again after the eighth, and then again after the twelfth, and after every fourth loading, it might last thirty or forty loadings.

Those are random numbers, picked for the example, and don't necessarily apply to any cartridge/rifle combination.

You only anneal the shoulder/neck area, as it is the area that does most of the expanding and contracting. You want the body of the case to be harder. Hard equates to "brittle", but it also equates to "strength". If you soften the body of the case, it might not have the strength to stand up to the pressure of firing, and can blow out. That would be a BAD THING.

[Caneman]

How often should I anneal brass?

[JLA]

Its completely up to the reloader. I happen to anneal and trim my match brass on every cycle.. But my 7.62X54 brass gets annealed and trimmed every 3rd cycle..

[JLA]

Originally Posted by jack404

JLA, thanks for posting this .. i'm gonna rip it off and PDF it and put it in the reloading section for all the want to reload folks

cheers and well done eh

No worries there jack. Id be honored..

[JLA]

Originally Posted by garydude

Excellent post Josh! Thanks for helping the masses understand annealing.

BTW, your little one is as cute as they come.

Originally Posted by Marlin T

JLA, that last picture is the best

Thats all on the outside I promose.. Hes a little hellian .. Never a day goes by that he doesnt make me smile though. He has a very unique personality and if you ever meet him its hard not to want to stuff him in your pocket and take him home with you..

[gdmoody]

Josh, thanks for posting this thread and Alpo, thanks for the answer on why!!

[gun-nut]

Ok my question. I have heard that with annealing the brass that its only best to do this if you only neck size. is this true? this is to get them... say 20 reloads out of them

[JLA]

I necksize most of my bolt rifle brass with 1 exception.. 7.62X54R. Those get a partial FL resize and annealed just the same.

I am currently seeing just how many reloads one can expect from quality brass that is necksized only and trimmed/annealed every cycle. I am up to 4 loadings and it still looks new. No visible signs of wear aside from the ejector mark on the casehead..

[Bindernut]

Originally Posted by gun-nut

Ok my question. I have heard that with annealing the brass that its only best to do this if you only neck size. is this true? this is to get them... say 20 reloads out of them

Nah, annealing is helpful if you full length resize too.
No matter what type of resizing you do, you're swaging the neck and running the expander ball through it. That process work hardens the metal twice as much as the actual firing process does.
Every firing cycle the neck gets "worked" three times...firing, sizing, and expanding. Pistol brass even more so since you're usually belling the case mouth and crimping the bullet.


I neck anneal like JLA shows in his original post. I usually anneal every 4th firing cycle for me...which is usually when it's time to trim to (depending on the particular rifle).
And I always water quench...I don't want the heat to creep back into the case body for the reasons that Alpo mentioned.
I don't use the Lee case holder, but that is a neat idea. I just use a good pair of leather gloves.

[JLA]

I use the case holder so I can spin the case at high RPM and heat the neck absolutley evenly. Plus I already have it chucked up for trimming. So it makes and easy 2 step fluent process. Then after im done I chamfer them as I toss them into the tumbler.

Gun-nut, Bindernut is spot on with annealing helping necksized and FL sized. Properly done, rifle cases should last at least twice as long. Provided you arent hotrodding the load and stressing the brass from overpressure.. I am expecting at least 15 cycles from my .308s.