Annealing.... again (w/ a twist)

[mehavey]

I've been satisfactorily annealing 30-38 caliber (308/30-06/300WinMag/375) brass for some time
now using the Hornady kit with the 475°F white Tempilaq. Brushed ¼" below the shoulder and
then heating the neck/shoulder uniformly, it seemed to give just the right mid 600's final neck
temp/effect before the 475° limit crept down the case to the lower-temp Tempilaq and the flame
was withdrawn.

See:
http://thefiringline.com/forums/show...34&postcount=8

Well, my 45-90 Starline cases require annealing -- immediately when using Black Powder --
or the gas/soot leakage back around the case is horrendous. (Even Starline advises annealing
these cases when using BP)

Since the case geometry and mass is so different w/ these large straight walls, I went directly to using
650° Yellow Tempilaq -- inside the case neck --and again spun the cases by using a piece of cleaning
rod chucked in a drill w/ a bit of masking tape wrapped around the end deep inside to give the case something
to grip while rotating.


[Note: trashed case used for pic example. Don't yell]

The yellow contrast is very bright in the light beam I shine into the operating area, and when the
inside of the neck hits 650°, that yellow goes out like a lightbulb and the case is dropped onto a towel.

This is all great.... except the brass doesn't show the characteristic "annealed" color, nor does it feel
annealed in either the sizing die, the expander die... or when the bullet is seated. Just the opposite in fact.
If feels as stiff (or stiffer) than ever and exhibits characteristic blow-by soot when fired.

Any ideas (Uncle Nick/Brian/others) ?

[Dan Cash]

I anneal in a similar fashion but put the Tempilaq at the lower limit of annealing on the case body. I am using 550 green. If I have the flame positioned correctly there is a faint coloration of the brass and the stuff is soft. You might try that with the inner, blue pencil flame just touching the end of the case. For me, it is a nominal 4-5 seconds. Big danger is getting the brass too soft. It will bulge when the powder is compressed.

[cajun shooter]

Did you do your annealing in a dark room so that you could see the color the brass was taking on and not relying on the product to tell you everything? Maybe you received a bad or weak batch.
I've never used the chemical on my 45-70 cases but perform my annealing in a darkened room so that as soon as the mouth shows color I know to stop.
I then drop the case onto a pile of old heavy towels. I prefer this way to using the water method.

['74 sharps]

Being a firm believer in the k.i.s.s. method of bpcr, I hold the case in my bare hand, giving it one turn in about five seconds heating with propane. Seems to work.

[mehavey]

Lower Tempilaq on Body: Doing that w/ the white 475F Tempilaq at case mid point -- but w/ the big cases that's now just a double check against heat creep as opposed to knowing the final temp in the neck region.

Dark Room/Color Change: I tend to shy away from that because it's subjective relative to the room light, the flame color, ... and my mood at the moment. (Besides, I grew up as a kid listening to the Springfield receiver problems due to workers trying to gauge temp color by sumer light vs winter light)

"...not relying on the [Tempilaq] to tell you everything? My problem is that Tempilaq is the undustrial standard, and it tells me the inside of the neck has reached 650+. Annealing (or at least relaxation) should have taken place.

OK, I'll try things again this afternoon using great care and attention to detail.
Film at Eleven......

[montana_charlie]

This guy shows you the 'simple way' ... which can be done in normal light.
Once you do one case that pleases you, you have a 'time to cook' figured out that you can use for all of the others.

A video http://www.youtube.com/watch?v=kgD5D0Wzu-c

[mehavey]

...the 'simple way'

That's a variation on tyhe theme shown in
http://thefiringline.com/forums/show...34&postcount=8
It works both with the 475F Tempilaq method (very exactly) and w/ the eyeball method (trial & error). It works in large part because of the different geometry/thermal mass of the neck vs the larger shoulder/case, which tends to slow down heat transfer between the two masses. This results in the sharp blue/gold separation below the shoulder being a good indicator of relative annealing condition of the neck above.

The massive straight-wall cases associated w/ the 45s don't have that advantage of mass & geometry, and tend to overheat before that blue border ever becomes apparent. (At leat this is my observation from some very-error filled trials). So solid/actual temperature measurement is critical, and fast heating is crucial if transfer down the case body is to be minimized. Unfortunately "Fast" and "Consistent" get to be a real challenge when judging by brass color.

So I've got some Tempilaq coming for 700° and 750° (which is where actual annealing occurs and the Giraud auto-anneal machine is calibrated.
http://bulletin.accurateshooter.com/tag/annealing/

As before -- Film at Eleven.

[mehavey]

The 750°F Tempilaq arrived today. Pale blue and fairly thin compared to the white 475° solution.

Painted it inside the neck, let it dry, then put the MAP torch on full 'medium' to get fast heat now that I had a definite "switch-off" indicator.

Spun a half dozen cases up watching for when the blue light disappeared, dropped the case in a towel , and spun up the next one.

I FINALLY got that slight discoloration on the first inch of the case that indicated an annealed condition and
sizing/expanding confirmed the sought-for uniform feel. The Postells seated smoothly groove-by-groove.

Film at Eleven after shooting tomorrow.....

[montana_charlie]

Now that you know what the slight discoloration looks like ... and how long it takes to get it ... you can do without the Tempilaq.

I have leftover Temp Stix and Tempilaq that I will probably never use because I got to the point where you are.

CM

[mehavey]

Not really in this 'particular' case. Done deliberately with an eyeballed "mid-flame"
MAP gas setting to get high/fast heat, I'll never get exactly the same flame
(and therefore time) session-to-setting setting. But the Tempilaq offsets
that by telling me the exact same brass temp cutoff point. (Besides, the
annealing discoloration/transition is more subtle than I would have anticipated.)

Were I doing a hundred cases in a session, of course, I'd do what you point out
-- set the timing on the first couple w/ Tempilaq and rest by time. So point well
taken.

Bottleneck cases are handled entirely differently.

[mehavey]

Film at Eleven:

I mentioned that the 750° annealing process left a veeeery subtle color shift on the brass -- hardly discernible.
That changed after firing/soaking/washing the cases -- which normally go dark, dark brownish from the BP/soap solution before tumbling
Now it's obvious:



That said, I also used these cases to re-test the compressed Swiss 1½ load under a different Postell bullet -- one I cast from that troublesome Lyman mould in a previous post:
http://castboolits.gunloads.com/show...83&postcount=1
only this time w/ a no-kidding Lyman#2 alloy and shot as-cast.

The result at 100-Yds in failing light this evening was OK:

[dagger dog]

No doubt Tempilac and other chemicals that change color works, another on the cheap method that works goes as follows.

Hold the case with tongs-pliers, slowly apply heat while rotating the case until you see the color start to shift, you may need to be in the shadows or away from bright sunlight but it's very evident, spit on your fingers and keep touching the case with the wetted fingers, if the spittle sizzles it's hot enough to quench, you can quench in water.

[John Boy]

mehavey - the next time you anneal, just do it down to the depth of a seated bullet. Annealing almost the half of a case is not necessary. The objective is to reduce the work hardened brass and have the mouth of the case seal against the chamber walls ... Okie Dookie?

[mehavey]

Actually, the flame is only applied to the first ¾ inch. But the heat-crawl effect -- even with fast-flame MAP gas -- still affects the brass further down as far as susceptibility to dis"coloring" differences from sitting in a dirty soap & BP solution.

The mouth, however, is the limited area that hits 750, and the coloring of a dirty annealed case (left) compared to that same case after tumbling (right) shows how subtle things really are.

[mehavey]

Of added interest that I noted today, the Lyman "neck sizer" that I use actually sizes half-way down the case.
http://www.midwayusa.com/product/466...-45-100-sharps
In other words, exactly to where the discolored brass line is located.

(Looks like I need to bring the sizing die "up" a bit.)

[Harv33]

Maybe I missed it but it seems like the Lead Pot Annealing is simpler and more exact temperature and depth wise ?.