Is this normal brass wear??

[Prieto9000]

This started to happen in one of my 6.5 CM rifles. I never had this issue before. Normally when brass was well used I had broken necks or loose primer pockets but never this.
It is just happening in one of my rifles but I don't mix brass between rifles, I have separate boxes of ammo for each one.
I'm using hornady brass and it has been reloaded around 5-6 times.
After the last reload this is happening to most cases. Not every case separates, but most of them show one of the following simptoms.

 

[gohring3006]

How far are you bumping your shoulders back?

 

[Weaselthis]

If several of a particular lot are doing that, IMO, you probably should toss 'em.

If you straighten out a paper clip and grind a sharp point on it, bend it into a small hook that will fit inside the case mouth, you can slide it down around the web and actually feel the "dip' in the brass that indicates it's about to separate. If you can't do that, you can cut one in half length wise and check for the ring inside that way.

As Gohring3006 mentions, shoulder bump excess MAY be the cause.
I experienced this in some 7-08 brass. I tossed all of them (200+ if I recall.....hurt but a LOT LESS than losing an eye)! I didn't trust them and they hadda go!

 

[gohring3006]

Once I got away from neck sizing and started bumping shoulders, one of the most important pieces of equipment in my reloading is a bump guage...

 

[Buckskinner]

Wow, you are lucky... I would have tossed them all after the first one, probably want to have your chamber checked out. Head separation can damage a chamber in short order... I assume you were able to get all of the remnants out of your chamber. How many did you shoot that separated?

As stated, you are bumping a bit too much. I generally bump .001-.002 only when needed and neck size if it is for a designated rifle.

 

[Prieto9000]

I haven't really measured how far back I'm pushing the shoulder. I used to neck size everything a few years back until I started having chambering issues on a 7 mag.
Based on your advise I just disassembled the remaining cartridges and tossed the brass. I also ordered a 6.5 neck sizer to see what happens.
I never had any issues using a full length die before. I thought you were supposed to get the case all the way inside the die and I had been doing it for years with no problems of any sort. I believe I learned a very valuable lesson today.

 

[JeffVN]

No that is not normal brass wear. I have some .308 (Lapua brass) with 15 reloads on them. I shave some .338 LM Improved cases (Lapua headstamp) with close to 20 reloads on them.

+1 I would toss the rest of the brass into the recycle bin since it will be the same as the brass pictured above.

Depending how many cases have separated I would be a bit concerned that you might have etched the inside of the chamber with all of that venting gas.

+1 again. If you leave neck sizing to full size the brass, you need to know how far you are pushing the shoulder back. Too far will eventually lead to case head separation like in the pictures here.

I use neck bushing, full size dies every time on every piece of brass, but I only bump the shoulder 0.001 to 0.0005. They chamber smoothly, and the sizing effort is minimal.

JeffVN

 

[elkaholic]

I haven't really measured how far back I'm pushing the shoulder. I used to neck size everything a few years back until I started having chambering issues on a 7 mag.
Based on your advise I just disassembled the remaining cartridges and tossed the brass. I also ordered a 6.5 neck sizer to see what happens.
I never had any issues using a full length die before. I thought you were supposed to get the case all the way inside the die and I had been doing it for years with no problems of any sort. I believe I learned a very valuable lesson today.

It definitely looks like a head space issue (shoulder bump). You can not really count on just bottoming out the sizer die on the ram because of tolerances in machining, even in the shell holder......Rich

 

[MagnumManiac]

There is ONE and ONLY ONE cause of case head separation, that is excessive headspace.
There are 2 causes, the rifle chamber, or excessive headspace induced by reloading.

The easiest way to determine a proper bump is to remove the firing pin assembly, size a case, clean it, chamber it and see if it's tight or not. If it's loose, back the die OUT, size another case and do as above by screwing the die in in 1/12 increments until the bolt just falls closed by gravity, then back the die OUT again 1/12 turn and lock the locking ring.
Each time, use a different piece of brass, if you use the same piece, it will work harden and give false indications through the bolt fall.

Cheers.
gun)

 

[Mikecr]

You should stop.
Pick up & read a how-to-reload book & start over with a plan (rather than luck).

 

[Broz]

+1 again. If you leave neck sizing to full size the brass, you need to know how far you are pushing the shoulder back. Too far will eventually lead to case head separation like in the pictures here.

I use neck bushing, full size dies every time on every piece of brass, but I only bump the shoulder 0.001 to 0.0005. They chamber smoothly, and the sizing effort is minimal.

JeffVN

This, ^^^^^^^^^^^^^^^^^ you most likely have your die set too low for the chamber on your rifle and are over sizing causing rapid brass flow and premature separation.

Here ya go: http://www.longrangeonly.com/how-to-adjust-and-set-head-space-and-shoulder-bump/

Jeff

 

[wallypedal]

+1 on what the guys just told you! Those cases only put up with stretching like that a couple times. Do what they say, don't believe that you'll get it right just by setting the die so it cams over. If you don't have a custom shell holder set, then you need to adjust the die instead. The chamber on the rifle with the separated cases must have been reamed a little deeper than your others - and it could still be in specifications. There are several variables at play here, and they can add up the wrong way. You were fortunate. I own a single shot break open Encore, and that is a whole new education on case life and possible separations. IF a rifle has been assembled with too much headspace, or right on max, and factory ammo produced with maximum sizing is fired in it, those cases will be stretched enough to affect case life if they are bumped back more than the absolute minimum. Not wanting to hijack or be a blowhard, so that's enough. Pretty sure you got the idea

 

[Prieto9000]

I just ordered the hornady headspace gauge kit and threw away the old cases and replaced them with brand new ones. I also ordered a 6.5 neck sizer to avoid bumping the shoulders back.

 

[Garycrow]

Very good

The headspace comparator will fix the problem if you use it to set up your full length dies to bump the shoulder .001"-.002". I prefer to use full length dies set up to bump the shoulder rather than just neck size. Eventually neck sizing only will result in cases that are hard to chamber and the should will need to be bumped to restore ease of chambering. I like to go ahead and bump the shoulder each time I resize to keep things consistent.

Another good option is a redding body die set up to bump the shoulder combined with a lee collet die or other neck sizing die. You maintain ease of chambering with the body die while the collet die gives you really straight necks resulting in minimal runout.

You might consider getting a redding body die to go with the neck sizer you just ordered.