On 8/23/2013 10:17 AM, John B. wrote:
On Fri, 23 Aug 2013 09:18:14 -0500,
wrote:
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.
Unless you are full length resizing the case all you need to do is
anneal the necks. The usual technique was, as Ed mentioned, to stand
the cases in a pan of water - reaching say half way up the case - and
heat the necks. when you get a color change then tip the case over.
The temperature really isn't that critical as all you are doing is
annealing the work hardening that you are doing when you expand and
crimp the neck.
If you are using lead bullets you are probably expanding the necks and
crimping fairly aggressively so you probably will be annealing more
often then a bloke shooting jacketed bullets.
It might be useful to measure the cases and trim to length and
possibly ream the necks, if necessarily, occasionally.
--
Cheers,
John B.
Thanks guys.
Yes, lever guns (headspace off of the flange!) tend to stretch the cases
over max length in only 3 or 4 rounds. So yes, full length sizing
and trimming to length (and yes, expanding (GENTLY!) the necks for
lead).
My latest effort is to start resizing so as to headspace off of the
shoulder. All that involves is setup for the full length sizer so that
the sizer matches a case fired in this rifle. That OUGHT to reduce the
amount of growth considerably.
Hadn't heard of "Tempilaq", but I'll go find some.
As for the pan of water device, I have built one that turns Lazy Susan
style, but I still need to build a DC speed control circuit to get the
speed under control. It takes a good six seconds for the neck to come
up to temp and they aren't staying in the flame long enough right now.
But even then it's too easy to get TOO hot TOO long and go dead soft.
I want to have a way to cross check the temp - at least until I have
enough confidence in what I'm doing!
I asked Santa Clause for an M1 Carbine for Christmas...
30 carbine is a cheap reload with few of the problems associated with
100 year old designs...
