Case Head Separation help

[pyrotechnic]

I have a question for some of you long time reloaders on the Hide.
I have been reloading for a decade or so and haven't had any issues with case head separation until now. For my .30-06 I have what started out as 500 pieces, maybe a little less now, of Winchester brass that I cycle through. I have been reloading this same brass since 2008 when I bought the rifle. I can't say for sure as I have moved a bunch since then but I believe I only have 5, maybe 6 firings on this brass. Most of the loads have been stout loads with reloader 22 and the 190gr SMK and more recently the 208 gr amax with H4831sc.

Little history,
I have always FL sized until the last two firings when I started neck sizing with the Redding bushing die. I have always had issues with some cartridges requiring some force to chamber, I attributed this to a tight chamber combined with my sizing die loosening up while processing the brass in one sitting. After Neck sizing for the first time on the previous loading, I decided to run all my brass through the body die that came with my Neck sizing die to ensure smooth chambering and I planned on neck sizing only until chambering became sticky again.

Next variable,
I upped my charge weight from 60gr of H4831sc to 61gr of H4831sc under a 208 gr AMAx after doing some more load development. During this load development I had a partially separated case head at 61.0 gr but attributed it to a bum piece of brass. No pressure signs, primers were still rounded on the edges and no ejector swipes.

I loaded up 50 rounds at 61.0 gr which I shot today. Out of the 50 I had 4 partial case separations and 15 cases that showed a visible white line where they were about to give.

My first thought is that the body die inner diameter is too small and overworked my brass, trashing it. I don't have a way to measure it other can calipers, but the base of the die measures larger than the base of my RCBS FL die. The body die measures 0.462 while the FL die measures 0.461. I know the dies are tapered so to measure the same point (hopefully) I stuck the calipers in until the flat part of the caliper was all the way into the die of the body, so the point I am measuring is approximately 3/8" into the cavity.

Summary:
Loadings 1-4 (or so): FL sized, 190gr SMK w/RL22, 208gr AMAX w/RL22
Loading 5: Neck sized only, 208 gr AMAX 60gr H4831
Loading 6: Body sized and Neck sized, 208gr AMAX 61.0 H4831sc Case head separations

My question:
Is this normal? From what I understand it is not. I have had much better case life from Winchester brass with stout loads in my .308. primer pockets usually being the first to go.
If this is not normal then what do you suspect is the culprit, or what can I do to figure it out?. I don't want buy new brass and trash it in a few loadings. At this point I am pretty suspect of the 400+ cases I just body sized and neck sized. 4 failures and 15 almost failures out of 50 rounds isn't really something I care to repeat for 400 more shots. Should I just cut my losses and be happy with 5-6 loadings and call it good?

Thanks,

Maarten

 

[arnie19]

The type of separation you have is from bumping the shoulder back more than needed .You should invest in a set of Hornady tools that will check your fired case and the you can compare that too your sized case .About .001 to .0015 is plenty of set back on a bolt gun .

 

[MitchAlsup]

First, before reloading any brass from this lot (again) use the paper-clip trick to detect thinning of the case web.

Second, I believe it is unlikely that the body die shrank the diameter of the cases, I also believe that the shrinking of the case diameter would not lead to ICHS. Those symptoms lead to body cracks.

Thirdly, the body die might have pushed the shoulder back too far, and this WILL lead to ICHS

So, you need a means to measure shoulder position, and there are a variety of tools that do the you well. I use RCBS case micrometers, other use Hornady dial indicator attachments,... What maters is not which tool so much as you have one and use it (to set up the die.)

{The paper-clip trick is to take a paper-clip and unfold one arm until it is straight.
Then take a pair of pliers and bend the tip 3-mm in length.
At this point you can stick the paper-dlip down into the case body and feel the inside body wall down near the web.
If you feel a divot (or a raveen) you have preICHS symptoms. Tread lightly!}

BTW I got 35 reload cycles out of my last 308 set of brass pushing 155 Scenars with 47.8 gr Varget... So you should not accept 5-6 reload cycles, you should figure out what in your reloading procedure needs fixing.

 

[Big Z]

It was a combination of excessive resizing and stout loads. I would personally cut my "losses" and start future loads with new brass with your new-found/better loading procedures and documentation. The first rule of resizing is to move only enough brass to ensure reliable function; slight resistance when locking the bolt is desirable for range duty. Save your primer pockets with lower powder charges, if you care.

 

[pyrotechnic]

Thanks for the quick replys guys. Gonna find a paper clip and sort through my remaining brass. Then invest in a a tool to measure shoulder position.

 

[scotharr]

The type of separation you have is from bumping the shoulder back more than needed .You should invest in a set of Hornady tools that will check your fired case and the you can compare that too your sized case .About .001 to .0015 is plenty of set back on a bolt gun .

WINNER! this is your answer. Make sure you have the correct tools to measure the headspace on fired and resized cases.

 

[trailrider121]

I have the same issues as you with case head separation in my 30-06, but mine is from over working the brass. I full length size every time(.002" shoulder bump), and run stout loads like you. I get about the same 5-6 reloads and start to see signs. I use the paper clip trick as a indicator after I size the brass. You will feel it get hung up inside. Using lower pressure loads does help with brass life.

 

[Tx_Flyboy]

Pyrotechnic,

MitchAlsup & Trailrider121 nailed it.

I experienced the same thing, but for my 308 & 556 loads (both stout).

I took a different tactic since i could not locate a case mic during the madness when all reloading items were sold out.

I actually managed to locate some case gauges specifically these WILSON CASE GAGE | Brownells

After the gauges arrived, i checked some of my prepped brass...you guessed it, they were oversized...case length was fine, but my dies were set up to bump the shoulder of the case too much leading to ICHS. Since using the tools, case head separations have gone away...completely. I am now up to 7-8 firings on my 556 brass and 308 brass and toss them when primer pockets loosen or when i get split necks...

My batch of 30-06 brass is in it's 5th firing, and no signs of ICHS.

Good luck and let us know how it turns out...

Also, when you are done experimenting with your 30-06 + H-4831sc loads, please post them up...i just accumulated 20lbs of that powder, 1,000 pieces of 208AMAX and a fewhundred 210s, 215s & 230Bergers

 

[damoncali]

Get a hornady comparator and set back the shoulder .001"-.002" as others have said. Also, your die should not be loosening up over a session. The first case should be coming out the same size as the last. If they are not, you have a problem in your die setup. And while a paperclip will do in a pinch, you'll get a LOT better feel out of a solid pick (not sure what the tool is actually called). You can get something at Home depot that looks like a small screwdriver but with a slightly bent spike instead of a blade. Makes it very easy to feel the inside of the case. A paperclip flexes too much.