Case Splits/Breaks

wjohnson1983 · May 27, 2017

Here is a picture of some rifle brass I have that split. These cases have been loaded a max of 5 times with some being less.

All of the cases came from a .270 bolt action rifle.

One set was 130 gr. Nosler Partitions; 55.0 - 57.0 gr H4831SC
The other was 150 gr. Nosler Partitions; 52.5 - 56.0 gr RL22

I was doing a ladder test for both bullets. Splits happened randomly on all different powder charges.

Bad brass? Reloaded too many times?

I'm thinking to chunk all of this brass and start anew? I've also heard to shoot some factory ammo to see if that splits.

burrhead · May 27, 2017

I'd definitely toss the rest of the brass from that batch. Are you setting the shoulder back too far? How did you determine the datum to head measurement for your chamber?

243winxb · May 27, 2017

This looks like a case head separation from the brass stretching to much on firing?

Can be caused by over sizing the brass, causing excessive Head Clearance.

Or the firearm could have excessive Head Space in the chamber. This can be checked by a gun smith.

http://www.brownells.com/.aspx/lid=...g_Success___Minimum_Headspace_and_Maximum_COL

Bart B. · May 27, 2017

Bart B. · May 27, 2017

You're setting fired case shoulders back too much. Cases stretch too much each time they're fired.

Read post 9 in:

https://www.thehighroad.org/index.php?threads/headspace.815278/#post-10440532

Start over with new brass. Set fired case shoulders back no more than .002" and 30 or more reloads each is possible with normal safe max loads. Back when the 30-06 wash popular in rifle matches, 50 to 60 reloads per case happened by minimally full length sizing fired cases. It depends ones attention to details and aptitude with reloading tools.

That whole thread will help you understand this problem.

Save that old brass for dummy rounds or bullet seating depth tests.

wjohnson1983 · May 27, 2017

Thanks folks. These were full length sized using the instructions with the RCBS dies.

I recently purchased a head space gauge and this will be my first chance to use it since purchase.

Bart B. · May 27, 2017

You don't need to use a headspace gauge to do what I suggested. Just a nylon bushing and caliper. Those die labels are nice, but not needed. Their picture shows how much to twist the die to change its height .002". Half that for .001".

The first time a new case is fired in your 270, the chamber headspace is about .001" greater than the headspace on that fired case.

Walkalong · May 27, 2017

Classic case head separation from moving the shoulder back too far. There are a lot of way of measuring where the shoulder is before and after sizing. Some simple, some fancy.

Here's my home made steel one similar to the plastic one in Post #9 Bart linked to.

Here is a plastic piece to do what Bart showed in the pics in Post # 9. It's made by CTS Engineering and is $7.

A good read about Incipient Case Head Separation here:

https://www.thehighroad.org/index.php?threads/incipient-case-head-separation.734058/
.

bbqreloader · May 28, 2017

Walkalong said:
A good read about Incipient Case Head Separation here:

https://www.thehighroad.org/index.php?threads/incipient-case-head-separation.734058/
.

Thanks for posting the link again. Lost a bunch of tagged threads when I accidently deleted them when I thought I was removing just one :fire:

Case Splits/Breaks

wjohnson1983

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burrhead

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243winxb

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Bart B.

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Bart B.

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wjohnson1983

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Bart B.

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Walkalong

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bbqreloader

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