Case annealing

[harrygrey382]

I want to anneal my cases, mostly to increase case life. I'm getting about 30% split necks from Federal brass in my 243 after 4 loadings. I'm going to see if annealing gets more loads out of them. Also, it can't hurt accuracy to have more even neck tension.

I've read up about it a bit, and have built a turntable to rotate the the brass so the heat will be even around the neck while I hit it with a blowtorch.

My question is regarding temperature. I know I don't want to heat it very hot - well cooler than glowing. Looking at the photo below of split cases I tested on - which case is best? 2nd or 3rd from the right? 1st is not annealed, 2nd is a bit of heat - you can see the colour has darkened a bit aournd the neck and shoulder, 3rd is warmer - the neck and shoulder have taken on a copperish colour almost like rose gold. I'm thinking this is the colour I want? The last I heated the **** out of...

 

[flashhole]

Mine generally take on the appearance of the third from the right. In a subdued lighting room you can see the brass "turn" the color you are showing. Sometimes it's not as obvious, that's what's good about using a controlled heat time. The process is more consistent as long as you expose the brass to the same heat in the same manner.

 

[MEHavey]

How many cases at a time are you planning for?
(It makes a big difference in practical solutions.)

 

[amlevin]

Invest in a Tempilstik that melts at 650 degrees. Available at any welding supply shop.

To rotate I use an Deep Impact Socket that the case fits into. Close enough to not rattle and loose enough for the case to fall out when I dump it into water to quench. Using a 1/4" drill adapter for 3/8" drive socket I turn the case using my cordless drill. With my torch adjusted to a small flame, hold turning case in flame with inner cone of flame directed at the shoulder I heat for 4-5 seconds and then quickly touch shoulder with tempilstik. It melts if the case is at least 650 degrees and leaves a waxy smear on the case that comes off with a flick of a fingernail when cool. I try to determine how many seconds it takes in the flame to just make the stick start to melt and then only use it to check my time every 10 cases or so. You can do 100 cases in a relatively short time. As for dropping in water, it's my choice. Some say not necessary but at least I know that no heat has migrated down the case an close to the shoulder. Since I clean in a liquid, using Stainless Steel Tumbling Media I'm going to have wet cases anyway as the next step is cleaning.

Don't guess, use either the "crayon" or Tempilac and be sure you getting enough heat with out having to over heat.

 

[jmorris]

Click on the photos for videos.

You want it to look like this one. Blue flame, neck turned color even all around, no glow at all and the base is not hot after.



This one is over done. Note the flame change color before the case glows, the first sign of too much.

 

[popper]

I remember (about 50 ys ago) an induction solderer - looked like a clip on ammeter - for soldering copper pipe. Just plugged into the wall socket. Clip it around the pipe, wait till the pipe started to change color and the add solder. Seems like this would be a great way to anneal brass and doesn't cost $100's. The unions probably got rid of it cause it was easy and fast.

 

[amlevin]

The old tool you're thinking of is no longer made. It was kind of a split coil that got hotter than heck.

Today, Rigid makes one that consists of two carbon "contacts" that cause the metal to heat due to the electrical current passing through it.

Not very portable so most plumbers laugh at it. There are a couple that have bought them and wish they hadn't.

The only benefit is that they are "flameless" and can be used for a repair job inside a wall.

For annealing they are no good as the points of contact are burned by the carbon contacts. Flame is still best.

 

[popper]

The old tool you're thinking of is no longer made. It was kind of a split coil that got hotter than heck.

Today, Rigid makes one that consists of two carbon "contacts" that cause the metal to heat due to the electrical current passing through it.

Not very portable so most plumbers laugh at it. There are a couple that have bought them and wish they hadn't.

The only benefit is that they are "flameless" and can be used for a repair job inside a wall.

For annealing they are no good as the points of contact are burned by the carbon contacts. Flame is still best.

The old tool you're thinking of is no longer made. It was kind of a split coil that got hotter than heck.

Thanks for the info, I won't bother looking for that one. I guess I will look for an inductance type now, or make one myself. I'll give the flame and drill method a try.