Impending Case head seperation - Pics

[ReaperDriver]

I finally got around to slicing up some of my Lapua brass to see what the inside looked like from my previous thread about splits in the case head. Here's a progression from good to bad:

Now all three in order to compare

Finally, here's some of the one's that failed...

 

[tomme boy]

Re: Impending Case head seperation - Pics

How many loads were on these, and how was your dies set up?

 

[Timo Turl]

Re: Impending Case head seperation - Pics

Nice to see pics of the warning signs especially for those new to reloading. thx

 

[vman]

Re: Impending Case head seperation - Pics

Thanks for the pics reaper... i was just reading your thread last night regarding your problem with this brass.

Amazing what a little over-sizing can do. That was the problem wasnt it?

 

[Grumulkin]

Re: Impending Case head seperation - Pics

Head separation is caused by the cycle of shooting, resizing, shooting, etc. If a cartridge case has to be trimmed it means the brass is going somewhere with resizing and that would be toward the mouth of the case since the brass at the head is much thicker. ANY sizing will cause brass migration but of course cases that are sized more will have problems with head separation sooner.

The photo shows a case that completely separated and one that would on the next firing. See the shiny ring near the head on the upper case? That's where the brass is going to separate.

To keep this from happening to you, use the wire (I use a paperclip) with the tip bent to 90 degrees. Run the wire down the inside of the case and you can feel the groove that starts in the early stages of impending head separation and you can discard the case before that happens.

By the way, though head separation is most common in bottlenecked cases, it can also happen in high pressure loads in straight walled cartridges.

 

[oneshot onekill]

Re: Impending Case head seperation - Pics

I had some Federal brass separate after the first time I full-length sized it. It was only reloaded twice total. Started a thread about it yesterday...

 

[308sako]

Re: Impending Case head seperation - Pics

Reaper, superlative work.

Federal brass: Seperation on a second loading would still possibly indicate gross oversizing, and the potential of a headspace issue in either the origional rifle or the second chamber if different.

 

[SONIC SAAMI]

Re: Impending Case head seperation - Pics

Your rifles chamber suffers from excessive head space.
Or your creating excessive head space pushing the cases shoulder back to far when resizing.

 

[ReaperDriver]

Re: Impending Case head seperation - Pics

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: vman</div><div class="ubbcode-body">Thanks for the pics reaper... i was just reading your thread last night regarding your problem with this brass.

Amazing what a little over-sizing can do. <span style="font-weight: bold">That was the problem wasnt it? </span></div></div>

Yes, I followed the die instructions to have the die touch the shellholder. DON'T DO THAT. It was definitely oversizging and bumping the shoulder too far, causing excessive headspace. Follow the reloading 101 sticky instructions instead. Works like a champ now.

 

[Victor N TN]

Re: Impending Case head seperation - Pics

RD,

Thanks for taking the time to cut those cases up and make the neat photos. Maybe the photos will help others understand what is going on with oversizing.

 

[FoxtrotBravo]

Re: Impending Case head seperation - Pics

Something I have been wondering about, since I am new to reloading: I've only been reloading .223 for bolt rifle so far, but when I size the cases, I notice the max resistance when the bottom of the die starts to go over the area of the case where the above mentioned separation occurs; it leaves a shiny band after sizing that is not there beforehand. I think this is just from the die rubbing on the case, but is this related to the progression towards head separation in some way? (I hope this makes sense!)

 

[John L]

Re: Impending Case head seperation - Pics

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: FoxtrotBravo</div><div class="ubbcode-body"> Something I have been wondering about, since I am new to reloading: I've only been reloading .223 for bolt rifle so far, but when I size the cases, I notice the max resistance when the bottom of the die starts to go over the area of the case where the above mentioned separation occurs; it leaves a shiny band after sizing that is not there beforehand. I think this is just from the die rubbing on the case, but is this related to the progression towards head separation in some way? (I hope this makes sense!) </div></div>

FB,
The marks on the outside of the case your referring to are NOT the same as what the OP is showing in his pictures. All FL sizing dies will leave the type of marks you describe. Now if your setting the shoulders back too far you will soon see the other type of marks on the lower portion of the case.

 

[John L]

Re: Impending Case head seperation - Pics

Reaper Driver,
Nice set of photos. Had this problem with some of my brass a few years ago. Got lazy in my sizing die set up. Results were what you showed. Cases seperated on the second firing. Cost me at the 600 yard line in a Leg match. Got a 6 o'clock 8 and missed shooting a 490 by two points and lost 2 leg points in the process. Lesson learned that day and I wont repeat it.

 

[ReaperDriver]

Re: Impending Case head seperation - Pics

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: tomme boy</div><div class="ubbcode-body">How many loads were on these, and how was your dies set up? </div></div>

Total on the Lapua brass was probably 10-12. However, this was the 2nd time through the same gun after I had the barrel set back and rechambered. However, I never changed the die setup to match the new chamber dimensions. The original die setup for the old factory chamber wasn't setup for it either, I just rant the die down to touch the shellholder with maybe a touch of overcam not knowing any better. I suspect I got away with it in the old chamber because of the sloppy dimensions probably kept it from being over pressure. But as soon as I loaded the round for the new chamber (and yes I re-worked back up) I was seeing pressure signs starting a good .5 grs below the old load. SO I think the tigher chamber combined with improperly (too much) headspaced brass caused these failures to manifest very quickly.

I know better now to actually set the sizing die for the chamber and not just to some arbitrary set of instructions from the die maker.

 

[tomme boy]

Re: Impending Case head seperation - Pics

I wish the die makers would really tell how to set up the dies. They know they are giving out some bad info on how to set the dies up. But the way they tell you to do it, the brass will load in all rifles. Just not how it is supposed to be for the gun it is going in to.

 

[vman]

Re: Impending Case head seperation - Pics

Problem is, how can a die maker just say go out and purchase extra tools to allow you to measure shoulder bump? They wont.

They cut dies to fit SAAMI specs but there are other variables involved. Differences in press ram heights, differences in shell holder heights, differences in chambers between different rifles and in general differences in how people set their dies up.

It doesnt take much at all to oversize brass, and to the new reloader taking in so much information, how is everyone to know.

 

[Clark]

Re: Impending Case head seperation - Pics

There are forums out there where posters claim that ramming the sizer die into the shell holder is the only adjustment needed.

Then the moderator agrees and locks the thread.

Did I mention the SKS and CZ52 are the finest weapons ever designed?

 

[johndoe]

Re: Impending Case head seperation - Pics

Great photos and thread! Well Done!