3rd loading; signs of head separation

[zepheris.hk]

Hey Fellas,

My casings all show signs of head separation with the ring around the base. Now this normally doesn't surprise me if I was on my 10th loading, but this was on my 3rd loading using new Lapua brass. No pressure signs were seen prior to the appearance of the ring.

Just wanted to see what others have to say. Whether it's my load, reloading procedure, or something else.

<span style="font-weight: bold">Background info:</span>
<span style="text-decoration: underline">Load:</span>
168gr AMAX
44.1gr Reloader 15 (Lot# 75138)
NEW Lapua brass (LOT# P00446002)
COAL: 2.005"
CCI LR primer
2.208-2.210" @ OG (in the lands) or 2.840" OAL
Chrono'd @ avg of 2720 FPS out of rifle below

<span style="text-decoration: underline">Rifle:</span>
20" Shilen match .308 1/10 twist 6 groove barrel on Savage action
Headspace set at MIN SAAMI SPECS using Forster headspace gauge

<span style="font-weight: bold">Other info:</span>
- 2 previous loadings were 43.1gr & 43.8gr of RE15 as I was doing some load dev.
-Brass has only been collect neck sized (NO FL sizing)
-100% certain that there was not a powder mix up
-100% certain that there was not a primer mix up
-My Winchester & PPU casings are on their 5th loading without any sign of head separation using the same procedures/components
-No flatten/cratered primers prior to the ring showing up

<span style="text-decoration: underline">Thoughts:</span>
-Is the pressure increase from loading them in the lands a major factor in this?

-Could it be that my load is too hot even without showing the normal signs? Looking at my Lyman 48th manual, MAX charge weight is 44.8 with given velocity of 2724 out of a 24" 1-10 twist barrel. My velocities are the same but out of a 20" barrel. I figured I was under max charge weight and no pressure signs so I was good, but am I mistaken?

-This is my first time using Lapua brass and this rifle is new so I don't have a baseline to compare against. Just wanted to see if this is out of the ordinary or not.

Any insight or feedback would be greatly appreciated.

Thanks,
Zepheris

 

[bohem]

Re: 3rd loading; signs of head separation

Varget is supposed to vary quite a bit from lot to lot. If you had some softer loads in a previous lot of the powder and you are seeing this now it's entirely possible that when you bought new powder it was faster and pressures are spiking sooner/faster.

 

[myerfire]

Re: 3rd loading; signs of head separation

RCBS makes a tool called "Case Master" It is used to measure the thickness of the case. Also simply taking a paperclip, bending a short 90* at the end and run that inside the case and feel for a ridge or thin spot where that ring appears. The appearance of a ring might simply be a blemish. Head separation after 3 firings doesn't sound right.
myerfire

 

[Victor N TN]

Re: 3rd loading; signs of head separation

Are you looking at a shiney ring around the case or have you actually checked it with a bent wire hook? I use a long dental probe with a small hook bent in it to see if the hook catches in any crack that may or may not be inside the case in that geberal area. I usually spin each case in my hand and check it at least three times (and sometimes four or five times if I suspect something), at different points around the inside. If you are really worried and still can't find a definite crack, cut it open with a Dremel tool. Split it down the long axis and have a look. Loosing a case or two isn't anything to what having your rifle blow up will cost you.

Good luck.

 

[zepheris.hk]

Re: 3rd loading; signs of head separation

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: bohem</div><div class="ubbcode-body">Varget is supposed to vary quite a bit from lot to lot. If you had some softer loads in a previous lot of the powder and you are seeing this now it's entirely possible that when you bought new powder it was faster and pressures are spiking sooner/faster. </div></div>

This is happening using the same lot, not from a new lot.

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: myerfire</div><div class="ubbcode-body">RCBS makes a tool called "Case Master" It is used to measure the thickness of the case. Also simply taking a paperclip, bending a short 90* at the end and run that inside the case and feel for a ridge or thin spot where that ring appears. The appearance of a ring might simply be a blemish. Head separation after 3 firings doesn't sound right.
myerfire </div></div>

How much better is the "Case master" compared to using the paperclip method?

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Victor N TN</div><div class="ubbcode-body">Are you looking at a shiney ring around the case or have you actually checked it with a bent wire hook? I use a long dental probe with a small hook bent in it to see if the hook catches in any crack that may or may not be inside the case in that geberal area. I usually spin each case in my hand and check it at least three times (and sometimes four or five times if I suspect something), at different points around the inside. If you are really worried and still can't find a definite crack, cut it open with a Dremel tool. Split it down the long axis and have a look. Loosing a case or two isn't anything to what having your rifle blow up will cost you.

Good luck. </div></div>

Thank you for all the input. I have checked using the bent paperclip method but could not find a definite "crack/line" or anything of the sort. I then cut the case open, but did not actually find a crack.

Is it suppose to be a clearly visible crack/line inside the case? Or just an "indentation" for a lack of a better word to it?

 

[zepheris.hk]

Re: 3rd loading; signs of head separation

Picture of the split casing:

 

[bohem]

Re: 3rd loading; signs of head separation

There's nothing there. No signs of case head separation, it's just a shiny mark on your brass.

 

[Victor N TN]

Re: 3rd loading; signs of head separation

I don't see anything on that photo to make me think it's a case head seperation. What you are seeing is just a shiny "burnished" mark on your cases. Do a search. There have been a lot of photos posted of both the shiny mark as well as the cracks before seperation.

 

[MitchAlsup]

Re: 3rd loading; signs of head separation

A: I see not case head separation on the cases
B: 2720 is a little fast for 168s in a 20" tube.
C: unless the sholder is pushed back its hard to imagine a pressure (or mechanism) that will longitudinally expand the already fireformed case in a min SAAMI chamber. However, a ring around the web is di rigeuer for cases operating relatively high in pressure.

 

[zepheris.hk]

Re: 3rd loading; signs of head separation

Thank you very much for your insight gentlemen. I was conflicted if I actually had signs of separation or not. This puts me at ease.

I will double check the velocities with another chronograph. I was nervous about that fact too, but no other signs showed up so I figured all was well.

 

[Innovative]

Re: 3rd loading; signs of head separation

zepheris.hk ......

This picture shows the early warning sign of headspace separation. It's much more obvious on the inside of your case, and it's much more common with belted magnum calibers.

The outside of your case usually shows a bright ring around the case, but not always. The real damage begins on the inside of the case. It's caused by excessive chamber clearance (at the shoulder).

If you don't have a borescope, you can use a sharp springhook to "feel" this ridge inside the case. Headspace separation can always be avoided by accurately comparing your handloads to one of your fired cases.

- Innovative

 

[Short-bus]

Re: 3rd loading; signs of head separation

I just had a case head separation in my rifle last sunday. I was using Lapua brass, and varget (1st time out with varget). I was on the 8th reload of the Lapua brass, and it's been FL sized every time. I finally got a Lee Collet die, and a redding body die so that I can get more life out of my brass from now on. I had no shiny ring, nor any indication from a paperclip that I was about to reach the failure point. I'm scrapping all my used brass to be on the safe side, and I have new brass here ready to be loaded.

I'm thinking about cutting all the old brass and looking at the case wall thickness and see if it was a fluke, or how close I was to more case failures.

Branden

 

[Country]

Re: 3rd loading; signs of head separation

You should buy a Doctors Otoscope . The thing they look in your ears with.
They are CHEAP! With that you can see the black shaddowy line on the inside of the case shown in the photo above , that is the start of case haed seperations. Sometimes you can't feel it very well with a bent wire and by the time you do feel it , it may be ready to go .
If you use both feel and visual methods you will pick them up early.
Having said that I think you have headspace issues.
Buy some new brass and don't size the case body . Seat the first bullets you fire into the lands to push the case right back against the bolt face. Once they are fireformed then you can seat off the lands. You may be oversizing your brass or the chamber is too deep.

 

[Country]

Re: 3rd loading; signs of head separation

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Dust_Remover</div><div class="ubbcode-body">I just had a case head separation in my rifle last sunday. I was using Lapua brass, and varget (1st time out with varget). I was on the 8th reload of the Lapua brass, and it's been FL sized every time. I finally got a Lee Collet die, and a redding body die so that I can get more life out of my brass from now on. I had no shiny ring, nor any indication from a paperclip that I was about to reach the failure point. I'm scrapping all my used brass to be on the safe side, and I have new brass here ready to be loaded.

I'm thinking about cutting all the old brass and looking at the case wall thickness and see if it was a fluke, or how close I was to more case failures.

Branden </div></div>
Firing 8 times and FL sizing 8 times is the same as firing it 16 times . Also as above I think you are oversizing and bumping the shoulder just a tad too much each time. For Autos you may have to FL siz.
However you are on the right track with the body die it will allow you to size the body with much greater precision and much less work hardening of the brass.

 

[Short-bus]

Re: 3rd loading; signs of head separation

What really sucks is that I had just annealed all my cases. I had fired 27 rounds of freshly annealed and hot loads without a problem, but just this one case let go. I'm not interested in testing my luck with the rest.

Branden

 

[Country]

Re: 3rd loading; signs of head separation

Yes it's annoying for sure. At 27 hot loads you are doing ok and I think it is wise to retire that brass. If I am reading it right obviously your sizing and loading technique is OK .

 

[Short-bus]

Re: 3rd loading; signs of head separation

Yes, I know my technique is fine, and I was well aware that it was time for new brass. I've been bugging my wife for a while telling her that I need to order more as I was (then) on the 7th loading, and since I was FL sizing each time, I knew I was going to be pushing my luck.

The old configuration of this rifle was neck sized from start to finish, and I must have loaded that brass 10 or 12 times, and never had a failure, but I never full length sized them once. This brass started in that rifle, but then I had some work done to it, and started over.

I'm looking forward to working with neck sized only brass. I've been getting the occasional 1/3moa groups when i've got my act together. Would like to see it get more consistent, and possibly better.

Branden

 

[Criver600]

Re: 3rd loading; signs of head separation

Minimum FL resizing and annealing I typically get 20 plus reloads out of my Palma brass. Its the primer pockets that finally go. Find an experienced benchrest competitor at your local club and get him to show you how to properly FL size your brass. If your pushing the shoulder back over .002 your wasting money.