I recently purchased a heat induction tool for use both at work and in reloading. I use it in reloading to anneal my brass. There has been some skepticism as to whether or not a readily available heat induction tool would be able to heat a cartridge enough quickly enough to anneal only the neck and shoulder area of a cartridge. Let me put that to rest; it works. Not only that, it works very well.
I am using a tool called the mini-ductor
which is made for auto mechanics. Somewhat common tool for us, although it is usually a piece of shop equipment and not something the tech owns.
I did an experiment tonight to show just how well it works. I took 7 pieces of unfired .308 Winchester brass of Winchester brand and put each piece into the coil for a different amount of time...
I timed the heating with various counts, counts were probably 3/4 of a second on average.
#0- Did not put into the coil, for reference only
#1- In coil, power on for a count of 1. Very slightly made the neck more golden.
#2- Power on for a count of 2. Starting to have spots that got hotter, slightly lighter in color
than the rest of the cartridge.
#3- Power on for a count of 3. Neck just ever so slightly turned pink at the very last instant of power on. I think that this one is just perfectly annealed.
#4- Power on for a count of 4. Neck turned dull red for the last 1/2 count. I think this one is overdone but I could see where this one is what we are looking for.
#5- Power on for a count of 5. Neck was bright cherry red, temperature started creeping down the case. After removing from coil a glaze formed on the neck (from overheating). This one definitely got too hot.
#6- Power on for a count of 6. Neck, shoulder, and top of case body all bright cherry red. Heat moved even farther down the case body, same glaze as number 5. This one is cooked. I can deform it in my fingers.
The verdict is that using a heat inductor is a very good way to anneal. Results were extremely repeatable and very fast. Cartridge #3 took about 8-10 seconds total between grabbing the case with pliers and heating it. I will be tinkering around with how to set it up to run automatically next. I'll be posting on my blog
and on here with updates.