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Case Annealing For Beginners - The Do's and Don'ts
Cartridge case annealing. A term that most of us gun nuts are probably familiar with. There are several reasons one might want to anneal their cases. If you are like me, you reload to save money. Annealing cases usually extends the case life. Extended case life means money saved. Then there are the guys who anneal to try to increase accuracy. These guys are much more picky about how evenly their cases get annealed. Uneven neck annealing can result in uneven neck tension, which can result in lost accuracy. For most of us, we will only be shooting out to maybe 500 yards. If you don't weight sort your cases, weight sort them again by water volume, de-bur the flash hole, uniform the primer pockets, turn necks and then weight sort a third time, you probably don't need to worry about 100% perfect neck annealing. If you do all the things I listed above, you probably won't mind spending $400 on a case annealing machine that will anneal perfectly uniform.
Some brands of cases come from the factory annealed. You will be able to see the difference in case color on these cases. Properly annealed brass that you do at home will also have a noticeable coloration difference on the neck and shoulder. The main thing to remember about case annealing; NEVER overheat the case head. A good rule is if you can't touch it, it's too hot. Heating the case head will lead to all kinds of disasters, mainly the primer pockets getting loose, but could also result in case head separation which can damage your gun. When annealing cases, its a good idea to keep the bottom 1/3 of the case in water. On short hand gun cases, I may cover up to 1/2 of the case.
Why Do We Anneal
When you were a kid, did you ever take a piece of thin metal and work it back and forth until it broke? Did we care why it broke? Of course not. Breaking bits of metal made us feel like Superman, and super heroes don't need to know why. Now, most of us being adults know that the metal broke because as it got worked back and forth, it became harder. The harder the metal it, the more brittle it becomes, until it finally breaks. Your cartridge case does the same thing. When you fire it, it expands, and then when we go to reload it, it gets squeezed back down in the sizing die. The neck has a even harder time, since it gets compressed smaller then it needs to be, and then pulled back oven by running it over a expander ball.Usually after a few firings and the series of expanding and compressing of the case they split. The most common area to split is at the mouth and the neck of the case, but sidewalls will rupture sometimes and case head separations are not a uncommon occurrence. We can make our cases last longer by only neck sizing, although that is really only a option for rifle cases. There is nothing that can be done to save a batch of cases that have begun to separate at the head, and they are honestly dangerous and should be thrown away. But a batch of cases that has only begun to crack around the neck and shoulder can be annealed to get more life out of them.
How To Tell When Your Cases Need Annealed
This can be the hardest part. Most of the time with my own reloads, I reload until I get a split neck, then I anneal the cases and keep shooting them until I get another split neck, and keep repeating this until the batch of cases is so small that its no longer worth reloading them as a group. at this point I throw them in a can for the caliber, and keep it set aside as if I loose a case in another batch of brass that are the same brand, I have a replacement.
There are other signs that your cases need annealed though. After sizing, if the expander ball pulls back through the neck extra hard, or if it seems to take more force then usual to seat the bullet, this could indicate that the necks are getting hard and that it is time to anneal.
Or, you can just anneal on a regular basis, say every 7 shots or how ever many you feel you can get out of a case without splitting the necks. I do this with cases that are hard to get my hands on, like my 32 mag cases.
The Common Methods
There are several different methods of annealing cases. As mentioned above, there are auto annealing machines, but they cost quite a bit of money, so for most of us, they are kinda out of the question. I mean who wants to spend 500 bucks when the point for most of us is to save money.
One method that I see quite a bit is taking a socket that the case head fits in nicely, and then spinning the case in a drill and heat with a blow torch to get even heat all the way around the case, and then drop it in water. I personally don't use, or trust this method, because for one, it takes longer, and for two it adds quite a bit of risk to over heating the case head. Heat travels through brass very quickly, and with the base unprotected from heat that way, to me, that puts the case head at too great of a risk.
Another method that I see, and have tried, is dipping the case in molten lead, holding it by the base, and pulling it out when the base gets too hot to touch, and dropping it in water. Okay, Reality check. Molten lead is usually about 750 degrees. I work as a welder, so am used to my hands getting pretty hot, and it was still quite uncomfortable for me to hold my hands that close to molten lead. After the first case I used a pair of pliers and used those to dip the case. and then we have the second problem I ran into with this method, lead inside the case. This wasn't really a problem with straight wall cases, but with bottle neck cases, I had problems with lead staying in the case just blow the shoulder, and this was quite a pain to get out of the case. The only solution to this problem that I found was to dip the case in oil before dipping it in the pot, which kept the lead out, but introduced a new problem of the oil fouling the powder. Plus, once again with this method, over heating the case head is still a problem.
Probably the most common way, is to take a pan of water, and set the cases in it so that close to 1/2 of the case is submerged, and the use a blow torch to heat the neck and shoulder. This is the method that I use, and the one I am going to try to explain in better detail
The process is actually quite simple. Take a pan (I use a metal cake pan), fill it with water to cover about 1/2 of the case, heat with a torch until it starts to change color, and then you can dunk it into the water to cool it, or let it stand. I let them stand. Cooling heated metal, of any kind does cause it to harden. Brass usually doesn't show as much hardening as other kinds of metal, it still does harden back up some, and that kind of voids the point of annealing.
I usually stand the cases in the pan about 2 inches apart. I'll start one one side of the pan, and heat all the cases till they just start to glow, and do all the cases from one side, then start back on the first case, and do it all again from the other side. And that's it. Size, trim and load.
There are other ways to do it. but that's what works for me. I get even heat this way, and have never had a problem with uneven neck tension. No matter what method you choose, just remember not to over heat the case head. Good luck and happy reloading!