On Fri, 23 Aug 2013 12:12:18 -0500, "Paul K. Dickman"
wrote:


"Richard" wrote in message
om...
My 30-30 brass, having been reloaded a few times, is getting work
hardened. I'd like to extend the useful life of the cases if possible.

I've read a lot about annealing brass, some of it quite contradictory.

So yesterday, I took what I think I understand of that and gave it a
try. I chucked up the shell holder from my Lee trimming tool in a
portable drill and fired up a propane torch.

As I understand it, I'm looking for a gold color change at the neck
(indicating 700 to 800 degrees?) , but without losing the shine from
the rest of the case - as an indication that the case neck has been
annealed but not the rest of the case.

When the color change happened, I dropped the case in a bowl of water to
stop the heat from continuing down the case and head. (Brass doesn't
"heat treat" like steel in that respect)

Spinning the brass seemed to give an equal treatment all the way
around (which should avoid hard spots in the neck area) , but judging
by color change alone I wonder about the consistency from one case to
the next.

I haven't seen an IR thermometer that goes high enough to monitor the
process.

Keep the case head below 300 degrees (F)

The critical temperature is 482 degrees at which the first changes in
grain structure can occur.

Annealing brass to "dead soft" will ruin the case.
It will be dangerous to attempt to shoot shoot cases.

Anybody have more info/helpful tips/ etc?

(Karl???)


BTW, I'm reloading mostly cast lead these days, and pushing those pretty
hard (trying to stay right at 2000 fps). That seems to work well and
give good accuracy.


Let's clear up some terminology. Annealing of cartridge brass occurs in the
800-1400 deg range. This fully softens the brass and is only something you
should think about if you're wildcatting.

What you want is called stress relief. This occurs in the 500-650 range.
If you are using a turbo torch, stop. These heat too fast and are too
oxidizing a flame.

Use a pencil flame torch, you want a soft reducing flame and you may have to
cover an air hole to get it.
Heat slowly and dance the flame around. As they heat, the necks will darken.
Eventually, you will see the darkening disappear as you play the torch
across it and reappear as the flame leaves, This is the temp you want.

You don't need to quench, but it is not harmful. On something as long as a
30-30 you would have to screw up big time to get the head up to any critical
temperature.

The shoulder should be fine in the same temp range but will probably never
get there.

The inaccuracies of torch heating and exposed surface area will leave you
with the crimp area softer than the rest of the neck, which is exactly what
you want.

You should not have to do this too often. It depends on your load and crimp.


Paul K. Dickman

Dead soft in the 3030 NECK and shoulder ......will harm nothing and
will prolong brass life many many times. I average 30 reloads from
regularly annealed (about every 10th firing) and neck sizing only

Ive got brass in the cases that have been reloaded at least 50 times

Gunner

"There are no leftists in mainstream American politics.

Just two right wing parties, one hard right and one softer."
Christopher A. Lee, 8/18/2013