It has been 18 months since I last annealed my .40-60 Maynard cases. Advice I have rec'd is that neck tension changes and the brass becomes too brittle so one should periodically anneal and some even suggested I should anneal after every firing. My cases were grouping tightly but if I anneal them I should at least extend the life of them. I also believed I should 
improve neck tension of my cases.
After annealing I belled my cases and reloaded them after annealing. I used fire formed cases and did not full length size them.
Shot them at a competition and my neck tension was not consistent. Groups were no longer tight and I started having flyers.

An old timer advised me I should have full length sized and then belled the cases twice before reloading to stabilize the neck tension after annealing the cases.
The softened brass needs to be work hardened slightly to ensure proper neck tension.

Do others get improved accuracy from only annealing fire formed cases or do you also need to fire them a number of times or work hardend the brass with your reloading dies to ensure consistent neck tension?

No I did not over anneal the brass. I heated it until it started bluing the brass but stoppped before it started to turn red.

It depends on what brass I'm using.  I seldom anneal my 45-70 Winchester brass.  Everytime I seat a bullet in them, they all feel very consistent.  Accuracy doesn't seem to change.  On the other hand, I anneal my 45-90 Starline brass every two firings. Bullets do not have the same feel many times when I seat them.  I swear that I seem to get better accuracy on the second firing but no way to verify this as conditions are always different at long range matches.
If IIRC, Steve Garbe wrote an article on annealing his 38-55 brass and he would size and expand twice before he reloaded them.  Bob

shovel80 wrote on Sep 23^rd, 2013 at 5:45pm:

+1, though I load my bullets into the lands by adding enough in the way of wads that I have to use one of Arizona Sharpshooters cartridge seaters. As close as one can come to actual breech-seating with fixed ammo.

Finger seating in the case definitely works best in my 38-56 and doesn't work-harden the case neck. Not sure about the 40-65 yet. Only way you will know with your rifle is to do the testing to find out. What works in one man's rifle may not work in another's.

My Shiloh in .45-70 shoots slip fit bullets better than with neck tension.  This might be because I've spent more time on developing slip fit loads though. 

I have recently started annealing my brass frequently.  Even for my slip fit loads as I think it's important for the case mouth to seal th chamber quickly and consistently.  I haven't noticed a difference with my Shiloh, but I think I might be seeing a small improvement with my CSA 1885.  I think it takes a number of groups to really spot a small improvement though.

I also tried a few ten shot groups where I was extremely picky with a new batch of brass.  I checked weight, rim thickness, length, thickness at the case mouth, and freshly annealed all cases.  My groups were just slightly worse than with my regular brass that was sorted only by rim thickness and length 

Chris.

As am shooting MOAnimal or mid-range with my BPCR rifles, not terribly worried about group size as long as it holds the X-ring. That said, if you do not have anything longer than 200/300yd for practice, group size 'generally' translates well to 500m or 600yd from those distances and group size is meaningful. My experience is that 100yd is too short to translate well to the longer ranges. 

As a matter of consistency, am annealing all new brass as well as the annual anneal.