Split Case neck (Reloading Advise)

[hunter399]

So went out for some target practice this mourning.
I only shot 12 times ,3 out of 12 had split case neck .
No sticky bolt or primers signs of pressure.
Brass has been reloaded 5+ times with no annealing.
Load is over max in reloading book. But never got split cases before.
Just looking for advise,groups seemed decent and not really look in to change it. Thinking my brass might just be brittle.

Any thoughts.

[MountainWalk]

Full length or neck size? Measuring your cases once sized?

[jrebel]

What caliber and how much over max are you?   5 times without annealing could be the answer especially with a hot load.

[BULLBLASTER]

Split neck wont have anything to do with pressure. Its from cycles of shooting and sizing. The rest of that lot is likely near splitting also.

[hunter399]

7mm mag
63 grains of hybrid v 100
162 sst
Full length resize

Lee reloading manuals says 60 grain max
Hodgdon says 58 grain is max.
My load would be max if I was using a 140 grain bullet.
Cronograph loads last trip. Was 62.5 grains ,MV 2970.
Didn't crono this time thought 63 grain would put me right at 3000 MV or close enough.
Group I got today was right at 1in moa at 100 ,just a budget 783 remington.

[hunter399]

Split neck wont have anything to do with pressure. Its from cycles of shooting and sizing. The rest of that lot is likely near splitting also.

Ya that what I was thinking also.
Thanks for reply.
I have some new brass .
That brass might be at the end of its days.

[BULLBLASTER]

You might be able to salvage what hasnt split if you anneal it. But if its already started to deform it might be too far gone.
Your rifles chamber neck is likely just a bit big, your sizing die a bit small or a combination of both.

[HighlandLofts]

Bottle neck cases do get brittle from being woked. With all that preasure you are doing good with the rounds used.

[hunter399]

Here's a pic of the cases.
And the steel plate been getting hammered lately.

[Nimrod]

Let’s see the primer and

[BigGoonTuna]

I had a batch of starline  7.62x39 that split just sitting on the shelf. This was virgin brass that I ran through a sizing die and loaded. Only thing I can think of is that it may not have been annealed at all.

[hunter399]

I just got done with annealing all of my old cases.
There is no doubt that they are flattened a little.
63 grains is what I'm calling max for my rifle.
And not advise or to be used in any other rifle.

[Magnum_Willys]

What is size of fired case neck vs loaded ?

Guessing its over .005 and with 5 cycles needed annealing.

Had necks on 338-378 crack on 3rd cycle even.

[hunter399]

I guess I should check that.
There outside shaking around in walnut media.
I will have to get back on that one.
I will measure and repost.
It sounds like I need to keep better track of how many reloads on brass.
This is first time it ever happened to me .