Case Separation Issue, please help newbie reloader

[Lucks]

I've only been reloading for about a year now, and during that time I have mainly been reloading Black Hills and Lapua brass in .308. Over the course of a year I have ended up with one bucket of BH and one bucket of Lapua brass. I have (stupidly) lost all track of how many times I have reloaded each piece of brass. I'm sure some unlucky pieces from the bucket have been reloaded many times, and some lucky piece have been reloaded just a few times.
I have recently started having a huge number of case separations after never having any before (probably 1500 rounds without any problems, and now like 1 in 4 separates). In fact, the first 8 shots the other day had 4 separations. I assume my brass is just playing out.

I did a little test with a NEW piece of BH brass today. I shot it and reloaded it 5 more times and then it separated. Does that sound about normal?

I've got a lot (700+ pieces primed and ready) of this mystery brass that I don't know how many times I've reloaded it. I'm about ready to throw it out, because I'm tired of brass separating in my rifle and I've already had one separate in my resizing die. Before I did I just wanted to ask if anyone knew of a reason why a rifle would seem to start spontaneously having case separation issues other than brittle old brass.

One other thing, I did recently start using this brass in a new rifle. The new rifle is a GAP built rifle and I had to tighten down my resizing die more than with my previous .308 (working the brass more) to get the rounds to chamber in it. Also, I up'd the powder charge a little on the load for this rifle versus my previous. I've had no pressure signs, unless case separation is a pressure sign!

Please help if you've got any thoughts or advice.
Thanks!

 

[desertHK]

Re: Case Separation Issue, please help newbie reloader

I am glad to hear that you are doing okay with all of those case head separations. Remember, you can always buy new brass. Can't buy new face, at least for now.

If your mysterious batch of 700+ brass that look even remotely like the brass on the right side, then I would definitely toss them. You can see clearly a bulging ring just slighly above the case head. That's impending sign for failure. Loading it hot, and working the brass hard is a receipe for early retirement of those brass. Lapua brass are very hardy. I have them up to 15+ already, but I don't work the brass that hard. Just neck sizing only.

Be safe.

 

[former naval person]

Re: Case Separation Issue, please help newbie reloader

I'd guess you are full length sizing each time. Try this...trim to minimum length after firing. Neck size with bushing or Lee Collet die. Keep shooting til the chambering gets a bit of resistance. FL size then, then repeat.Neck size till the resistance begins to build, then FL resize and trim. You'll get a lot more reloads, I'll bet. JMHO

 

[Lucks]

Re: Case Separation Issue, please help newbie reloader

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: DesertHK</div><div class="ubbcode-body">If your mysterious batch of 700+ brass that look even remotely like the brass on the right side, then I would definitely toss them. You can see clearly a bulging ring just slighly above the case head. That's impending sign for failure. </div></div>
No, none of the brass has looked like the one on the right until this last round of shooting. Now when I shoot them... they either split, look like the one on the right, or look normal... about equal amounts of each.

Thank you for your advice, in the future I will definately keep up with how many times I fired my brass.

Being a newbie, I was just waiting for the necks to split and then throw them out...I thought that's what I was supposed to be looking for. I didn't know about this separation thing until it started happening to me.

 

[Victor N TN]

Re: Case Separation Issue, please help newbie reloader

If I were a guessing kind of person I would say that you have your sizing die set too short. That will cause you to over work the brass each time you size it. The result is a flowing of the brass from just forward of the extractor groove. After a few firings the case thins in this area and then it lets go. That's the most common place for cases to thin and crack.

Splitting case necks is caused by work hardening the brass. That's a different animal.

At least consider getting a dial or digital caliper and a Hornady / Stoney Point headspace guage. This way you can measure your fired cases and your sized cases. There should be ball park of .002" difference. .003" and over, you're stretching the brass.

I'm glad you weren't hurt.

Good luck.

 

[Jonlow209]

Re: Case Separation Issue, please help newbie reloader

Gosh that looks dangerous. I am new to reloading and I dont want to thread jack or anything but do these rules apply to semi-autos too? Like can I just neck size the brass a couple times before full length sizing? What do you guys do with your semi-auto reloads?

 

[madd0c]

Re: Case Separation Issue, please help newbie reloader

The general rule is full length size for semi-auto. I am sure there are some with match grade chambers who are neck sizing for their ARs, but for reliability, FL size.
Depending on the gun you may not only have to FL size, but also use small base dies, I have to for my M1a.

madd0c

 

[desertHK]

Re: Case Separation Issue, please help newbie reloader

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: MacBud</div><div class="ubbcode-body">Gosh that looks dangerous. I am new to reloading and I dont want to thread jack or anything but do these rules apply to semi-autos too? Like can I just neck size the brass a couple times before full length sizing? What do you guys do with your semi-auto reloads? </div></div>

That's why I always inspect the brass each time before I reload them. When in doubt, toss them. With semi rifle, you need FL resize to chamber them reliably.

 

[Jonlow209]

Re: Case Separation Issue, please help newbie reloader

Would you say making the cartridge overall length a little longer by not seating the bullet more towards the lands not safe? I have a semi auto with a max cartridge length of 2.299 to fit in the magazine but I want to push the bullet a little close to the lands.

 

[Bacarrat]

Re: Case Separation Issue, please help newbie reloader

My guess is that you are oversizing the cases like Victor says. You need to get something like the Hornady gauge to know how much you are pushing the shoulder back when you full length resize. Don't go by the instructions that came with the die.

The Hornady gauge works, and I also use the RCBS unit and from what I have been told is a better method, but get's expensive if you have several calibers you are loading for. I know there is a unit someone else sells that uses a dial indicator to measure the bump, but I forget who makes it.

RCBS:
http://www.midwayusa.com/viewproduct/?productnumber=574297

You take a fired case, throw it in the mic, turn it down until it stops and get the reading off of it. Write it down, it doesn't have to be at zero, it's just your reference number. Take the case out and resize the case. It should reference a different number once you have resized it. You will then adjust the die by the readings after you retake the reading off of the mic. Adjust your die up and down according to the original fired case reading. Usually most people will resize their cases .001-.003 from the fired size.

 

[Greg Langelius *]

Re: Case Separation Issue, please help newbie reloader

As for the 700 cases you have and what to do with them, there is a simple test you can perform to find out which ones are suspect.

Take a piece of maleable wire (I use a paperclip), and straighten out enough of it to reach to the bottom inside the case. Bend a small right angle, maybe 1/16"-1/8"long, in the end to form a feeler or finger. Run the feeler up and down inside the case wall in the region where the separations are occurring.

In impending case head separation develops what we call a 'precursor groove' in a ring configuration at a particular around the inside of the case in the area that exactly corresponds to where the separation will occur.

Any evidence whatever of such a groove is a warning to immediately remove that case from circulation.

Unfortunately, the symptoms you've been describing would suggest strongly that you're going to find this groove in most (perhaps all) of your cases.

Back off your F/L sizing dies until fired and resized case will chamber with just a detectable smidge of added bolt drag upon closure.

Although I don't feel especially comfortable about decapping unfired primers, it may be possible to do this and recover some or all of them from the rejected cases. Eye/ear protention, obviously.

Even once you're corrected the die adjustment, it still makes excellent sense to periodically perform the feeler test. Properly resized brass should not experience its point of failure as a case head separation. Ideally, it will be the necks which go first, and if the loads are running especially hot, then it will likely be primer pocket expansion.

Noting that the GAP requires a more aggressive sizing operation, it makes sense to adapt the process differently for it than other rifles, because forcing all brass to fit the GAP will have the above consequences in looser chambers.

Because I dislike such issues, I have deliberately chosen to limit my rifles to SAAMI spec chambers in all cases. There's a small sacrifice in accuracy (maybe), and considerably less headache and confusion.

Honestly, I don't shoot well enough to garner the advertised advantage inherent in specialized equipment and handloading techniques.

Many of us don't, and I'm willing to admit it in public.

Greg

 

[bohem]

Re: Case Separation Issue, please help newbie reloader

The oversizing of the brass is a potential culprit as has been mentioned several times, and by all means, you need to check that.

Another thing to check is that you have an appropriate headspace in the first rifle.

The GAP is fine I'm sure, as this is something that would be checked/inspected before it left their shop. The factory rifle may be on the long side of the spec, or it might even be out of spec.

I've seen new factory rifles have case head separations after mild loads in a 223. Turns out the headspace was 0.009" too long. A few factory loads separated, and after a couple of reloads almost all of them separated. It ended up going back to big green for a checkup, they said it was 0.009" out of spec. This really means it was more like 0.015+" from the middle of the spec.

Long story, but check your headspace on the factory rifle.

 

[samnev]

Re: Case Separation Issue, please help newbie reloader

I would get a Wilson head space gauge in 308 to set up your dies to make sure you are not moving you shoulder back which would cause your head seperations. The factory instructions you get with dies are not always the best way to go.I get more than 5 reloads with my 308's without any problems. The bright ring near the head of the case is a sure sign of a probale head seperation.