Home Forums Hunting & Shooting Ask The Gunwriters DNA Candle Case Anneal

Tagged

Rimmed cases like the 30-30 don't work real well this way. Too much wobble. Others are fine. Count to 6, dump. Count to 6, dump.

Makes sense but the only rimmed cases I have is 22 LR and shotgun shells.

Picked up a DNA lamp from Lowe's that seems to work pretty well. I don't have Tempilaq on hand, and am basically using the "drop the case onto a wet towel as soon as it gets too hot" method. A few questions if anyone has guidance:

1. There still seems to be a good bit of heat transfer to the base of the case after you remove it from the flame- how do you know if the base of the case is getting too hot? Don't think I've had a case base get too hot to pick up yet, but they're pretty warm.

2. I have one batch of Hornady brass that takes a ton of force in my press to FL size. Even getting them that hot, they still seem to take a pretty good amount of force, especially on the downstroke. Is this an indication that I'm actually not doing as much annealing as I think I am?

Thanks in advance for any input!

The original article that mentioned the candle method was published by Fred Barker in PRECISION SHOOTING magazine. He developed the method with Tempilaq, and discovered that if he held the case (or whatever size) halfway down its body with the tips of his fingers, then dropped the case when his fingertips got a little too warm, it annealed the necks but left the base pretty much cool.

You do NOT wanted to anneal case heads, because they're supposed to be hard. If you do anneal them, the cases are likely to come apart when fired at typical modern rifle temperatures.

That's why brass manufacturers anneal the neck AFTER the cases are fully formed. The several stages of forming work-harden the rear/head of the case sufficiently to be safe, but make the necks so hard they would tend to split even after one firing.

That's definitely not the case with the 6.5 CM or .243 cases I've tried this with so far- I drop the case onto a damp towel as soon as it gets too hot to hold around the midsection, where upon it hisses for a second and starts to cool via ambient air and contact with the towel. However, enough heat transfers from the neck to the case head that the entire case gets what I'd describe as hot. I do suppose some 400 degree Tempilaq would be the way to determine whether my case heads are actually getting above the temp range I want.

I strongly suspect, though, that I'm not getting my brass hot enough to cause any damage or even fully annealing- I did some last night in a dark room and never detected the "red glow" guys mention by the time I was removing my cases from the flame, and the case heads were never hot enough to be painful to the touch. Also, as mentioned, brass still takes a considerable amount of force to resize.

I'll ask what case lube you are using OXN. I'm a dinosaur so I still use RCBS lube applied by rolling on RCBS pad, use a bore mop to lightly apply case lube to inside of neck for expander ball to pull through on die sets with ball.

Clean inside of neck using mop w/pvc solvent to remove lube, dry clean cloth to clean outside of case. Remember, I'm a dinosaur so I don't mind all the manual labor.

The "red glow" actually means the case neck is getting over-annealed--a common misconception that arose from many old-time writers describing putting the cases upright in a pan of cold water with the shoulders and necks exposed, and then using a torch to heat the necks until they glowed. But brass does NOT have to get that hot to anneal, which you would discover if using Templiq. (That old method also advised tipping the cases over in the water to finish the annealing process, but brass does NOT require quenching to finish the annealing process, unlike some other metals. Instead it anneals just the same if allowed to air-cool.)

Yes, the case heads get warm when using the finger-method, and continue to warm up a little after the cases are dropped. But they do not reach annealing temperature during the short period of time they're relatively hot. That was another thing Fred Barker checked out when devising the method.

They're still hell on fingers.

Awesome, thanks so much for the input! Not a metallurgist or anything but it seemed off the top of my head like it would take more than the 700-800 degree annealing range for most metals to visibly start glowing.




Currently using Hornady Unique case lube for the case body and just a tad on the exterior of the neck. I also give the inside of the necks a light spray of Hornady One Shot at a 45 degree angle before resizing.



Also, for anyone's SA who may be wondering, this setup was $16 at Lowe's and seems to work great.

If you want some more up-to-date information on brass annealing, including the chemical basics (which often vary from "common knowledge") there's an entire chapter in my BIG BOOK OF GUN GACK II. This includes the result of various methods from Fred Barker's candle technique to the A.M.P. (Annealing Made Perfect) electronic machine from New Zealand, which runs around $1500. The book is available from www.riflesandrecipes.com, and also includes quite a bit of other handloading information.

OX,
I used the candle method for years. At some point I bought 750 and 400 Tempilaq to see if I was actually annealing or over anealling. About 6-7 years ago I bought a Anneal-Rite. With the candle method one holds the case a lot longer and and it allowed the heat to migrate further down the body When using 750 inside the neck and a stripe of 400 down the body I found the Anneal-Rite heated the neck so quickly the heat does not get the chance to migrate down the body as far. I have not used the DNA candle method though.

Casey,

Here are some quotes from the GGII chapter on annealing:

"Brass anneals at temperatures as low as 480 degrees, but the process takes much longer. Even annealing at 600 degrees requires an hour, far too long for our purposes. Instead, we want to quickly heat necks to just under the melting temperature of zinc [787 degrees], more than 1000 degrees under the melting point of copper. Over-heating brass can actually melt out some zinc, turning the brass permanently soft.

"Annealing brass doesn't involve heating to a single, precise temperature. In a way it's like cooking pork: Many people "know" pork needs to be heated to 160 degrees Fahrenheit to kill trichinella larvae--but 160 degrees is merely the temperature that kills the larvae within seconds. Cooking pork to somewhat lower temperatures for longer periods also whacks 'em."

Which is why I discuss several methods of annealing in the chapter, and their advantages and disadvantages.

Thanks John, now I'll have to reread that chapter while I eat dinner!