Reply with quote #9
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.
Reply with quote #10
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.
Reply with quote #11
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.
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.
Reply with quote #12
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...
Reply with quote #13
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.
Reply with quote #14
the color change should be the same if brass is polished same. your brass with the most color change looks about right.
Reply with quote #15
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.