Over annealing cartridge brass

[adrexco]

Back in the 70's in high school metal shop we did the brass hardening and annealing work shop. We work hardened the brass by bending. If you bent too much it fractured. Once work hardened we heated until glowing bright. One sample set was allowed to air cool, a second oil bath cool, and a third water bath cool. As you can imagine each sample set had a different hardness. Air cooled was ductile, oil cooled was moderate, water cooled was hard. My point here is annealing is the controlled cooling to create a target hardness. It's not so related to how hot the start temperature is (with reason, you can't melt it). It would be interesting to see what hardness new brass is, verses air cooled, oil cooled, or water cooled. Anyone have access to a brinell hardness tester?

 

[BountyHunter]

If you do not have a quality annealing machine where you can set and control the heat, better use templaq to monitor what you are doing.

You can tell if they are too soft once you try to resize and seat a bullet. If no neck tension, you are asking for trouble to try and use them particularly on a hunt.

 

[Colcalcipherol]

I wouldn't anneal before the first firing, I'm sure it's done when forming the brass.
I'm out of the country at the moment and cannot look at my brass. I do anneal after a couple of firings.
The one thing I can tell you about making Jamison brass last as long as possible is not to run it hard (primer pockets loosen quick). Sounds like common sense but I can tell you it isn't as tough as Bertram brass. My Jamison brasswhere are you buy got put up for emergency purposes once I tried Bertram.

I'd love to use Bertram brass but **** it's expensive. I paid $1.90 ea. for the Jamison through CheyTac. What are you paying for Bertram and where are you buying it?

 

[Bravo 4]

I have purchased from IQ Metals and Midwayusa. I just checked both sources and Cheytac, it's all gone up since my last purchase about a year back.

 

[WildRose]

I have had to anneal thousands of cases for customer ordering rifles in my 338 Allen Magnum when Jamison made my brass for me. They basically made me 375 Cheytac brass but with my 338 Allen Magnum head stamp. The problem was with one order of 5000 pieces of brass that came in with case necks and shoulders that were WAY to hard. When they were necked down and fireformed, small cracks would form in the neck/shoulder junction making the brass useless.

Normally, when you anneal brass, you want nothing more then a dull red color. If your seeing anything that resembles orange or yellow, your getting your case mouths to hot.

Now, how hot is to hot........ Well, that greatly depends on the brass at hand. The brass I mentioned above needed an anneal that I would consider FAR to hot and with most brass would completely ruin the case necks ability to hold a bullet at all. But with these cases, I had to heat the cases up this hot and it was perfect.

A couple things I have learned over the years annealing brass. First off, I do not use a fancy case neck annealing machine for couple reasons which I will not go into here but I prefer to use a drill press.

The case is simply mounted in the drill chuck and then you turn the drill press on, apply the torch flame directly to the case neck and then you simply adjust the position of the flame to determine the amount of heat you have on the neck. Heat the case up until the neck reaches the color you want and then, and this is different then most, I pull the flame and at the same time hit the case with about 100 psi of compressed air from my shop compressor. This INSTANTLY drops the temperature of the case to a low enough point that you get the proper amount of annealing locked into the metal of the case.

I like this method mainly because I hate getting water inside my cases. If they are virgin cases, not a huge deal but if there is any carbon fouling inside the case when you dunk it in water, you have to really be careful to make sure the inside of the case is completely dry and this usually takes a chemical bath or TIME and most of the time, I do not want to take that time!!!

One advantage to using a drill press is that you can adjust the RPM level which will help you control how fast the neck heats up. You can take a propane torch of a given BTU level, and on X RPMs it will heat a case neck up to the proper temp in lets say 7 seconds. Now, for the experienced annealer, this may be perfect, but for the beginner, it may be to fast, simple fix, adjust the RPM range faster. The faster the case is spinning, the longer it will take to get the temp up in the case neck and you will have more control of temperature as you will have an easier time visually monitoring the annealing process.

Now, about heat soak and its dangers. You only want to anneal the first 1/3 of the case. That being 1/3 the length of the case from the mouth down. Now, this is max, if you can get away with it, 1/4 total case length is better but as long as you do not see the case discolor more then 1/3 the total length of the case, you will be fine. In all honesty, as long as your finished cases are annealed at least past the case neck, in most applications your fine.

Using the drill press, the Drill chuck will act as a heat sink and you will know when its time to take a break and let the chuck cool down.

The key to using this method is to heat the case neck up as quickly as you can and comfortably monitor your neck colors during annealing and then cooling off as quickly as possible as well. This limits the amount of heat that works down the case body.

I have NEVER had a case that annealed more then 1/2" past the neck using this method. Always point the torch at least horizontal or slightly down, direct heat toward the neck of the case or neck/shoulder junction unless the goal is to anneal the case shoulder for a specific reason.

Most importantly, if your not comfortable annealing the cases, do not do it unless you have someone experienced with you to walk you through it for a while. Once you get experienced, you will know the color your looking for for the right anneal.

Now, back to the proper color for the case being used. What I have found is that most commercial brass should only be heated to a very DULL red color. Its best to anneal in a rather dark room with JUST enough light so you can see what your doing. The darker the room, the more accurately you will be able to monitor the case color and therefore, you will have a more accurate annealing job.

If you get a case neck to hot, it simply will loose its ability to contract in any way which means when you press a bullet into the case neck, the neck will expand to the point where it will not hold a bullet as you will be able to move the bullet by hand.

If you do this, that does not nessesarily mean you have spoiled the case. For example, if your using a case that is based on an entire family of chamberings, there is really a pretty simple fix. For example, say your annealing a batch of brass for a 270 Win and you get the necks to hot and they will not hold a bullet any longer. Simple fix, get a 25-06 FL sizing die and run your cases through that FL die so that the case necks are reduced to 25 cal but DO NOT bump the shoulder. Then run your cases through your 270 WIN FL sizing die again to neck them back up to the original dimensions. Usually, this will work harden the brass just enough that it will now hold a bullet solidly enough to fire and be useful. Once that case is fired with a high pressure load and resized afterwards, it will be good to go.

Have found that necking up a case workhardens a case more quickly but I have also found that necking up a VERY soft case will more often result in a collapsed shoulder.

Necking down first does not workharden the brass as quickly but its also easier on the case with less chance of shoulder collapse so I generally prefer that direction to try to salvage over annealed cases.

Sorry for the long winded post!!! Hope there is something worth a **** in here for someone out there!!!

Some things can't be properly explained in sound bites.

The internet is filled with "how to anneal brass" articles and videos both of which are all too often just recycled and repackaged bad information.

The above quoted post is not one of them.

Good job as usual Kirby.

One thing that cannot be over stressed or repeated too often is to not heat the brass much below the shoulder.

I was taught the same 1/4-1/3 measuring from the case neck opening downward.

I've also found as you have that different makes of brass will vary quite a bit as to how much heating and for how long is optimal due to slight differences in the metallurgy.

 

[jasent]

I did a test to prove to myself what would happen if NECKS were "over annealed"

I heated neck and shoulders of 308 lapua brass to a point of an 8 second long, mid-to bright orange glow. While doing this the case body and heads were protected from the heat to insure we did not create a dangerous situation with softened case bodies. Assisting me was a national level f-class shooter who owns an annealing machine, and declared the brass we just annealed was surely ruined.

I loaded the brass with the same load that I used previously, and fired a 5 shot sub 1/2moa group at 100 yards. yes the neck tension was lighter, by feel of seating bullets, than it had been previous to the "over annealing" but non the less they held the bullets with-out slipping and the accuracy was unchanged.

If you think you annealed the body of your brass throw it away, if you think you over annealed the necks you just might shoot the brass before you pass judgement.

ive done the same. Even anealed with a cutting torch before. As long as you don't melt your necks or let the heat sink past the shoulder you can't do it wrong. I've gone way past the above post did. All shot as they did before anealing and still shooting those brass. There are a lot of myths about anealing. Don't believe the hype

 

[Canadian Bushman]

That post by kirby was a very big help for me at the time he posted it. Maybe one of the single most helpful post ive ever read.

 

[WildRose]

ive done the same. Even anealed with a cutting torch before. As long as you don't melt your necks or let the heat sink past the shoulder you can't do it wrong. I've gone way past the above post did. All shot as they did before anealing and still shooting those brass. There are a lot of myths about anealing. Don't believe the hype

This simply isn't true.

Here's a very good article on the subject.

The Art and Science of Annealing

Here is another.

http://bisonballistics.com/articles/the-science-of-cartridge-brass-annealing