How far do you go annealing bottle necked brass ?

[toallmy]

I have spent the morning lost in the archives getting more and more confused on a simple question , so I'm just going to ask . I generally shoot rifles that the brass is pretty easily replaced when the neck starts hardening so I have always just scraped it and started on a new batch , even my simple case conversions don't require any special treatment , so I haven't really done anything more than play around with case annealing on scrap brass .
Now I have recently started playing around with a 7x57 and ordered up a 100 new R-P cases to start with knowing that the R-P brass seams to harden in the neck faster than some other brands but it is what was available at the time .
Well a few days ago a friend sent me a few 7x57 cases he has had for years , left over from his loading experience with a old mauser . In this batch there were 40 PMC , 10 FC ,and 12 RP full length resized ,trimmed , and primed ready to load . I decided since I just put a scope back on the rifle to try it out , I would use a few of the odd ball brass . With a light charge of Unique trying to get on paper I loaded up the dozen RP + 10 FC after firing I discovered that 6 of the RP brass had a slight crack ' a small hole ' in the neck while the FC brass was fine .
This brings me back to my question - considering I'm going to be using a 100 round batch of RP brass , I have decided I'm going to try my hand at annealing brass , to extend its life .
When annealing brass how far down on the case do you go ? Chasing the blue line just to the bottom of the neck , on the shoulder , or a 1/4 inch lower than the shoulder .

[Reverend Al]

I anneal my cases to just below the shoulder so that they look similar to factory annealed brass such as Lapua, etc.

[toallmy]

It seems most manufactured brass , I have noticed run a little below the shoulder as you mentioned . As a little experiment the 6 RP brass that were not damaged , I tried annealing them until the blue line was a little below the shoulder around a 1/4 inch and the neck and shoulder were the golden brass color . I will see if this helps . If so I have some other brass that might meet my little propane torch .

[popper]

Was it pin holes in the neck? Had a bunch of R-P used 30/30 brass I used to load half-jackt plinkers with unique. Got circular cracks after pin holes developed in the necks. IMHO it is pressure in the neck for the shallow seated boolits. Most of the sizing/expansion occurs at the boolit base. Note to self, keep the base at the shoulder.

[toallmy]

A few were loaded with jackets that I pulled and dumped the powder out of the FC and RP , but I didn't keep track . Honestly the brass looked like new that's what surprised me seeing the small cracks on half of the RP brass after firing it . Well even though he only reloaded it a couple times it was probably 30 years old .
I want to do a little experimenting with annealing brass any way this is as good a reason as any . I have my new 100
RP cases in 2 - 50 count lots 50 of those have been fired once and the other 50 are processed but not fired yet . That seems like a perfect control group to test . I think I will try annealing one of the 50 count boxes every few firings just to compare brass life and effect on target over time .

[EDG]

I have never noticed the issue you had with R-P brass except for a few new boxes of .221 Fireball that had cracked necks. New brass in the box that cracked on the shelf.

My annealing sort of copies US military brass. Because it is a hand held process I get variation between 1/8" below the shoulder to 3/8" below the shoulder. This includes thousands of USGI .30-06 converted to 8x57 and 7.65 Mauser. Other cases include .30-30 formed to .30 Herrett too.

I have maybe 10,000 other RP cases with never any cracks. However I never store loaded brass if I can avoid it.

[waco]

Going a bit below the shoulder is what you want. 232565

[toallmy]

I have never noticed the issue you had with R-P brass except for a few new boxes of .221 Fireball that had cracked necks. New brass in the box that cracked on the shelf.

My annealing sort of copies US military brass. Because it is a hand held process I get variation between 1/8" below the shoulder to 3/8" below the shoulder. This includes thousands of USGI .30-06 converted to 8x57 and 7.65 Mauser. Other cases include .30-30 formed to .30 Herrett too.

I have maybe 10,000 other RP cases with never any cracks. However I never store loaded brass if I can avoid it.

I have used RP brass quite a bit over the years , and it seems as if I get neck hardening pretty constant if loaded 3-5 times over a few years . The expander doesn't want to come out of the resized case without a fight .
I'm not implying that there is anything wrong with RP brass , Although I do find it a little harder .
Hopefully annealing will extend the useful life of my brass .