What have I done? How do I fix?

[Tribe]

Stats:
Winchester 300WM Brass
4x Fired
Full Length Resize - Redding
76gr H1000, 208 Amax, CCI Mag

Rifle: AIAWSM 300WM


Out of about 20 fired from this loaded batch of 100, approximately 50% look like #3.

#1 is clearly the worst... the tail end is nearly completely severed, also, note the dimple near the shoulder - there are no signs of this on any of the other cases...

Any help, specifically in regards of how to fix, moving forward, is greatly appreciated.

 

[Triman2008]

Re: What have I done? How do I fix?

You got this from firing them?

I had something similar, but it dimpled coming out of my FL resize die(to much lube). The instructions I go from the majority of people was to reload it and shoot it again. The dimple went away after the next time being shot.

Like I said earlier, if this is happening when you shot them, I readlly don't know. I would inspect the case and see of any other signs of damage, wear, etc...and try slhooting it once more. Hope this helps.

 

[BobinNC]

Re: What have I done? How do I fix?

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Tribe</div><div class="ubbcode-body">Stats:
Winchester 300WM Brass
4x Fired
Full Length Resize - Redding
76gr H1000, 208 Amax, CCI Mag

Rifle: AIAWSM 300WM


Out of about 20 fired from this loaded batch of 100, approximately 50% look like #3.

#1 is clearly the worst... note the dimple near the shoulder - there are no signs of this on any of the other cases...

Any help, specifically in regards of how to fix, moving forward, is greatly appreciated. </div></div>

Tribe,

Which problem? The dimpled shoulder or the partial head separation? Both may have the same cause, way too much Full length resizing, so your setting your shoulders back.

Bob

 

[MitchAlsup]

Re: What have I done? How do I fix?

What I recommend is to use the bent paper clip tip as a tool to feel if the case has thinned near the base.

If it has, like I suspect, that whole batch of cases is junk. Cause: too much sholder setback--die set in too far.

Second recommendation, get a case sholder measurement device and use it to set up the die.

 

[Tribe]

Re: What have I done? How do I fix?

I'm not concerned about the dimple... just thought it may be a symptom of the problem, that my cases seem to be blowing apart.

Mitch - What do you mean by using the paper clip?

I thought, if you just want to run a "Spec" sizing, you just set your FL die at the base of the shell holder and go.... No?

 

[BobinNC]

Re: What have I done? How do I fix?

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Tribe</div><div class="ubbcode-body">I'm not concerned about the dimple... just thought it may be a symptom of the problem, that my cases seem to be blowing apart.

Mitch - What do you mean by using the paper clip?

I thought, if you just want to run a "Spec" sizing, you just set your FL die at the base of the shell holder and go.... No? </div></div>

Yes, it is part of a symptom, too much FL sizing and setting your shoulder back. Powder gas is leaking out and dimpling your shoulder. Whether it is coming from the partial head separation or past your neck and shoulder area, is a moot point.

And no ,you just don't screw the die down till it hits the shellholder. You size your brass to fit your gun, and resize no more than necessary. Or you get head separations like you got.

Picture what happens when you have a chamber that is on Max end of in spec, and a sizing die that's on the small end of in spec. Well you get what you got.......

Buy a dedicated neck sizing die, and FL resize only when it's needed.... Or learn to set your FL die to partially size your case.

How do you set your die to partially size your case? By trial and error. Back off your FL die, until it just sizes maybe 1/4 to 1/2 way down the neck. Then see if it fits your chamber easily. If not screw you die down a 1/8 of a turn at a time, and lather rinse and repeat, until the partially sized case slides into the chamber with little to no resistance.

Bob

 

[Fuzzball]

Re: What have I done? How do I fix?

"I thought, if you just want to run a "Spec" sizing, you just set your FL die at the base of the shell holder and go.... No?"

For a "Spec" sizing, yes. But, if you want to properly resize, set the shoulders so they match or are a thou or so below fired position to greatly reduce case stretching and avoid dangerous head seperations. IF you work carefully you can use the chamber itself as a resizing gage.

To get it right, the best and simplist way is to use one of the various gages for checking fired and resized case shoulder lengths. The RCBS Precision Case Mic, Hornady LnL or Sinclair Case Length gage (to be used on a dial/digital caliper) or the Innovative Technologies tool with a dial indicator are all good tools.

 

[former naval person]

Re: What have I done? How do I fix?

1+...and throw those other cases away. You can erode your chamber by firing until they separate. JMHO

 

[al redneck]

Re: What have I done? How do I fix?

Depending on rifle your headspace can vary alot. Some rifles of mine have run from '0'-'+7'. I have also had to surface a few thousandths of some shellholders to get the .001-.002 shoulder setback that I want. I have never reloaded belted rounds so take this with a grain of salt but if you only move the shoulder back .002 then no matter what you won't get excessive stretching of the brass leading to case separation. A trick us old guys have used for years is to straighten out a paper clip ( I use a .025 welding rod ) and put a 90 degree bend in it and then insert it in the case. When you 'drag' it along the inside of the case you can feel a narrow indentation. This is where the web is thinning. Most will trash the case if they feel this or call it their final loading. You can buy several different gages to measure headspace. I recommend the RCBS Precision Mic, about $44. You can use it to set up different bullets to whatever distance you want from the riflings, eg .010, .020,touching. It will also show you headspace of brass fired in your rifle and allow you to properly set up your dies so they won't have excessive stretching. I have read that some only get 5 reloads with 300 WM- I have no experience with this caliber. I can get 10+ in 308 Win. Hope this helps.

david

 

[Tribe]

Re: What have I done? How do I fix?

Thanks guys... I really appreciate the input.

The reason I've been FL sizing to begin with, is that I wanted to avoid really tight tolerances... I've seen, and experienced, enough problems in dirty/wet/etc.. field/match conditions, that decided I was just going to run "spec" and be done with it ... so are we saying that if I want to run "spec", I can only expect a few reloads.... or would "better" brass be the ticket? Or am I missing the point?

 

[Tribe]

Re: What have I done? How do I fix?

Thanks for the trick David... I was posting while you were...

I've done the too much lube thing before.... wouldn't it have flattened out when fired?

 

[BobinNC]

Re: What have I done? How do I fix?

Tribe,

Nothing wrong with running "Spec". But brass life will suffer. No free lunches in reloading. To get something (i.e. running Spec) you avoid tight tolerances, but get shit for brass life. Run tighter tolerances, you get longer brass life, but may have problems in some field conditions.

However, you could run RWS brass. It is hard to find, but runs an average of 30 grains heavier than 300 Mag Lapua brass. It's friggen tough brass. But your max loads will run two to three grains lighter, for the same velocity.

But even RWS brass won't fix a max "in Spec's" chamber, and brass resized with a min "in Spec" die. Eventually you run into head separations, sooner or later.

Bob

 

[BobinNC]

Re: What have I done? How do I fix?

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Tribe</div><div class="ubbcode-body">Thanks for the trick David... I was posting while you were...

I've done the too much lube thing before.... wouldn't it have flattened out when fired? </div></div>

Yes, it would have flattened out on firing, so therefore, it's not from too much lube, as the case has not yet been resized, but from gas leakage....

 

[Tribe]

Re: What have I done? How do I fix?

Long story short, my understanding is.... this is a headspace condition, and I am going to have to find my own happy medium between brass life, and taste in tolerances...?

I just wanted to make sure that I wasn't being a dumb-ass (wouldn't be the first time), or that it wasn't perhaps bad brass, or something to do with the rifle itself....?

I've been going back and forth, between buying cheap brass, and not fretting over tossing it... verses "good" brass, in hopes that it lasts long enough to be worth the additional expense....

 

[BobinNC]

Re: What have I done? How do I fix?

Tribe,

Yes, you have to find "your" happy medium. But don't be too quick to dismiss that it maybe the rifle or the dies. Rifle chambers are cut with reamers. Your's was cut in England to CIP spec's. That reamer had a min and a max allowed. Let's assume your chamber is on the MAX side.

Your die was also cut by a reamer to SAAMI min and max spec's. Let's assume it was cut to min spec's.

So now you have a max spec chamber coupled with a min spec die, and you are now way oversizing your brass causing head separations after 3-4 reloadings.

All this means is that your Spec load, developed with your brass, is too small for the chamber of your rifle. It does not mean you got a bad die, or a bad rifle. But the combination of the two produces a reloaded round that is undersized for that chamber. Your tolerances are too lose....

This is not a brass problem. This a reloading problem that requires you to develop a reload that more closely fits ( ie tighter tolerances) the chamber of that particular rifle.

Nothing unusual or weird. Sometimes you get a rifle and die combo thats right in the middle of all spec's. And sometimes you get what you got. Adjust for it and press on.

Bob

 

[Tribe]

Re: What have I done? How do I fix?

.....and the rabbit keeps runnin' down that damn hole...

 

[softcock]

Re: What have I done? How do I fix?

... " <span style="font-style: italic">Powder gas is leaking out and dimpling your shoulder</span> ".

Big +plus on that. The gas flowing down the Neck and over the shoulder & body . Done that before on the Mags. when I have over done it on the FL sizing & overworked the Brass past it's prime .
.

 

[wnroscoe]

Re: What have I done? How do I fix?

Look very closely at the cases just above the rim. You'll see from a slight line to full separation. Discard these cases and do not fire them again. Your bumping the shoulder back too far when you FL size.

 

[MitchAlsup]

Re: What have I done? How do I fix?

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: wnroscoe</div><div class="ubbcode-body">Look very closely at the cases just above the rim. You'll see from a slight line to full separation. Discard these cases and do not fire them again. Your bumping the shoulder back too far when you FL size. </div></div>

This is what I was implying with the paper clip trick, those cases look like toast.

Not mentioned, yet, in this thread is that beled magnums are headspaced on the belt and not on the sholder. When a cartrige like a 308 is sized too short, it will fail to fire in the chamber. When a belted case is sized too long, the case will expand; sometimes with less than desirable consequences.

The paper clip trick is as follows: Take a peper clip and straighten out the long arm. Now take a file and sharpen the nose of the arm. Finally take a needle nose plier and bend the nose so that it will fit down the neck of the case and can be used to feel the case wall thickness way down in the case. If you feel anything other than a straight wall, the case is toast. The cases in the OP image are toast, you can see the insipient separation in the image.

 

[6.5x61Super]

Re: What have I done? How do I fix?

I.C.H.S.


Incipient Case Head Separation


What's important is that you DO NOT BUMP THE SHOULDER OF YOUR BRASS BACK TO FAR CAUSING EXCESSIVE HEADSPACING BETWEEN THE BRASS SHOULDER AND THE FRONT OF YOUR CHAMBER. Because when you do that you cause the brass to become overworked from the constant stretching when fired and being pushed back excessively everytime you resize it.

 

[Swan]

Re: What have I done? How do I fix?

Sinclair Bump Gage inserts/tool is your friend.

 

[FreshKills]

Re: What have I done? How do I fix?

If you don't feel resistance on a sized hull,you are purposely crafting a seperation.

 

[Fuzzball]

Re: What have I done? How do I fix?

Headspace problems are, or should be, irrelivant to a reloader who will resize his cases correctly.

Any reloader thinking anything but the shoulder of a bottle neck case, rimmed, rimless or belted, should control his headspace is making a mistake that will cause head seperations much earlier than should they should.

I have some .243 cases I've fired some 10-12 times with no sign of any body stretching. I have some 7mm Rem cases I've fired 8 times, no significant case stretch or chambering problems. (I do neck anneal after each fifth time.)

 

[FreshKills]

Re: What have I done? How do I fix?

I much prefer to control headspace on a 22Hornet via land engagement,than either it's rim or "shoulder". punch it K-Hornet and that focus changes a smidge,though I'm still kissing.

The first poke is the money maker and there's much to be said for headspacing a false shoulder out of the gate.

 

[Tribe]

Re: What have I done? How do I fix?

Thanks for all the input fellas... been busy reassessing my game plan over here...

 

[dontstrokeme]

Re: What have I done? How do I fix?

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Tribe</div><div class="ubbcode-body">.....and the rabbit keeps runnin' down that damn hole...

</div></div>


I am painting the roses Red!!!!

Sort of makes me think of having a set of chamber based FL dies made.....no?

 

[cav has been]

Re: What have I done? How do I fix?

One thing found to increase case life on belted manglums is to fire form the cases to start with. If one uses the light load of pistol powder/ cream of wheat method, this can move the shoulder forward gently. Thereafter permitting said cases to head space off the shoulder rather than that counterfeit belt invention.

 

[Tribe]

Re: What have I done? How do I fix?

Could be.....