Dealing with reloading components isn't a 1-2-3 science, especially so for cases. In fact it's more of a semi-scientific art than most other activities.
Of course it can be done by the numbers but I do it by feel. If we do that, we must have a good deal of exprience and that takes time.
I can tell when it starts geting "too hard" to pull an expander plug out. Then it's time to anneal, no matter if the case has been fired 10 times or just 3. You can develop that feel too but you will have to accept that you will get a few split necks that earlier annealing could have saved for awhile longer.
I anneal all the cases in a lot at the same time, when the first cases show neck hardening is getting out of hand I figger they all need it.
I anneal after every firing of a case. The reasons for me are pretty simple. 1. It helps me keep consistent neck tension thus increasing accuracy. 2. The process really doesnt take that long. I have a set up that in about 15 min I can have 50 cases done. Considering I spend much more time in other case prep, whats 15 min? 3. I get to play with fire. 4. Its easier for me to track. I know that after everytime its fired it gets annealed so I dont have to try and guess or figure out how many firings it has been since the last time it got the heat. 5. I truly believe it really really extends my case life. Since I included this in my loading process I have yet to split a case. 6."Rich DeSimone, who holds the 5-shot IBS 1K world record, advocates frequent case-annealing: "On my 1,000-yard cases, I anneal every firing." As quoted from "6mmbr". I figure if you hold or held a world record in shooting you have some idea what you are doing. I am a copycat!
I'm still getting the hang of it - and am disappointed to hear that maybe I need to do this each timeI load....
I use a plumbers propane torch that takes a little backpacking stove gas can.
I understand some guys use mapp gas.
Mine seems to work fine. It only takes about 13-15 secs in the flame. I guess with hotter gas I may need to stop almost before I've started. I hear some guys say 5-7 secs with hotter torches, but that's total hearsay.
I anneal about every 5 - 10 rounds, using MAPP gas holding the case in a cordless drill and shellholder, drop it into water. Takes about 5 secs each case. BUT some folks claim MaPP gas is too hot. The secret is to not let the neck turn cherry red. You need to watch closely and stop when it is still orange.
When my velocity extreme spreads exceed normal levels it is time to anneal.
I dont watch the brass under the flame, I let the flame itself tell me when enough is enough. The flame will start to change color when the brass is the right temprature. With a typical plumbers propane torch at full strength, it only takes a few seconds.
IMHO if you wait to see the neck orange in normal light, youve gone to far. The neck will be too soft to be consistent. In dim light when you just start to see it change color, it is time to remove the heat.
Water quenching while convienient, is not neccesary for the annealing process.