annealing

[strobes]

I have done some annealing on my .308 brass and see that my groups are opening now.
I didn’t use the temp-sensitive lacquer and I guess no experience produced inconsistent results.
So two questions:
Is any one in Plano,TX area has annealing equipment so I can fix the brass that I have for a fee or a favor? And what local store would have temp-sensitive lacquer if any one knows?

 

[spclark]

'Fixing' annealed brass isn't worth the trouble. Brass hardens from being worked, not any kind of treatment as with steel or other alloys.

It's easy to 'burn' brass if it gets too hot so the temp indicating lacquer is worth it; try any welding supply store in your area, or you can get them on-line from places like this:

http://www.airgas.com/browse/product_list.aspx?catID=381&WT.svl=381

Brass needs about 650°F to anneal & doesn't benefit from quenching, just let it air-cool. If it begins to glow it's too hot!

On a clean case, you'll see a color change at about the right temp in a propane flame. That's enough; takes about four to six seconds,on a case being rotated at moderate RPM by an electric drill) with the flame set for about 1/2' - 3/4' inner 'blue' cone. Run the tip of that cone just off the shoulder of the case, with the case pointing away from the flame so the heat is going up to the shoulder & neck.

 

[strobes]

--'Fixing' annealed brass isn't worth the trouble. Brass hardens from being worked, not any kind of treatment as with steel or other alloys. ---
I was trying to say that with no experience my brass has different levels of annealing. I'm sure I did not apply enough heat. Running brass thought correct equipment will produce uniform results.
And thank you, I know where to look for temp indicating lacquer now.

 

[243Mendoza]

I have done some annealing on my .308 brass and see that my groups are opening now....

I also have very little experience annealing but my hand-annealed Win 308W brass will shoot 5-shot groups in the teens or low 2's.

 

[strobes]

Steve, did you use Tempil staff? Are you in Dallas area?

 

[243Mendoza]

Steve, did you use Tempil staff? Are you in Dallas area?

No, I dont Tempil. I twist the case's neck/shoulder near the top of the inner blue flame for about a second or two until it faintly glows in low light. I live in the Seattle area.

 

[strobes]

Ok, I'll try this, thanks

 

[strobes]

Is this brass look OK for use with loads near max pressure?
This is my second try and I wanted to hear from people with experience.
Two pictures of the same batch with and without flash.

 

[spclark]

It doesn't look like the brass is burned,overheated) but to judge something like this from a photograph is probably foolhardy.

What I do see is your annealing appears to extend down the case body more on some cases - particularly those in the middle of the group - than at the ends. I try to anneal each case as much like the one before as the one after. I takes a deft touch & care with positioning in the torch flame, as well as close observation of the change is surface color and the time spent actually in the flame.

Did you use any kind of temp-indicating product when doing these? It may help until you get the knack for consistency to put something on the neck and just below the shoulder that tells you when each area reaches a certain temp.

 

[strobes]

spclark,
I think one of my problems is that the flame was not hot enough so this is why the brass was annealed farther down while I was waiting on faintly glows of the brass in low light condition.

 

[spclark]

If you're using propane it's hot enough. MAPP or oxyacetylene are TOO HOT unless your process is very tightly controlled as to time.

Brass doesn't need to glow to anneal properly, in fact if it does it's likely overheated & subject to something called 'nitrogen embrittlement' which is to be avoided.

If you can see a slight change in surface color as the shoulder & neck heat up, that's enough.

http://www.6mmbr.com/annealing.html

You need reach only 600-650°F to effect the annealing you want. That's well short of where it begins to glow even in a darkened environment.

 

[Preacher]

The ones of yours in the center that have that faint Blue line on them are good, but mine run that line down a little further.... Even Ken Light asks for that faint Blue line to appear when using his annealer...
The one on the left is a new case ready to fire form...

 

[spclark]

Yep, that's how my cases look when they cool off.

Sometimes the blue is hard to see, particularly if I'm using old LC Match items, but the distance below the shoulder is the same.

Another condition to be wary of with over-heating is annealing that extends too far down the case walls. You don't want that to occur.

Some folk stand cases in a shallow tray filled with water to reduce the potential, then tip cases over once the flame has done its work. Annealing brass isn't like with other metals though; a water quench has no effect on the annealing achieved.

 

[jb]

the color change should be the same if brass is polished same. your brass with the most color change looks about right.

 

[CPorter]

I have found that sometimes the annealed brass needs more neck tension or a jam into the lands to get a consistent burn and good groups.