Case separation

Ruger007

Ruger007

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Had my first one yesterday. Was a fouler shot.
Rem 700 308
Didn't even notice till i opened the bolt.


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The batch (200) of Winchester brass is in it's 5th loading. I checked all the others with a piece of wire. Only found one that was even the slightest bit questionable.

No damage to face or gun.
Checked with my guages. It's not a head space issue with the gun.

Bought a headspace comparator now to set up dies better
Should be here tomorrow.

Could this have been a one off?
 

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I had one with a brand new Lake City 55 FMJ .223 round just the other day. That and a couple through the old Lee Enfield are the only I have ever had. Impressive considering all the other lame things I have had happen throughout the years. You are lucky the front portion came out easily. Even with a broken case extractor they can be frustrating.
 
Pressure, wall thickness, headspace, etc are all possible culprits. If this is a .5% failure rate of 200 cases after 5 shots, you now have a baseline for other failures.
 
Watch for a shadow or bright ring on the web of the other brass. You can usually spot thinning on the outside before it separates
 
Below my $100.00 bent paper clip :) for checking stretching and thinning in the base web area. It is a multi-function RCBS case mastering gauge and measures many things.

I bought this when I started shooting and collecting the Enfield rifle.

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The Winchester .303 British factory loaded case below stretched and thinned .009 on its first firing.

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Below you zero the gauge and it gives you the case thickness in thousandths and shows any thinning.

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Winchester's quality control has dropped off badly in the last few years and I would say you "MIGHT" have some defective cases. "BUT" it could also mean you are bumping the case shoulder back too far that allows the case to stretch beyond its elastic limits.

Below the Winchester .308 case failed after the 14th firing. And a Hornady cartridge case gauge allows you measure your fired cases and set the die for minimum shoulder bump.

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The cheap way to measure headspace is with a deprimed and trimmed square 44 Rem Mag case and a set of cheap digital calipers. The 44 case works well enough for the 308 case family all the way to the belted magnums. Other pistol cases work too, or any other round bushing that sits on the middle or so of the shoulder.

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Buckmastr said:
The cheap way to measure headspace is with a deprimed and trimmed square 44 Rem Mag case and a set of cheap digital calipers. The 44 case works well enough for the 308 case family all the way to the belted magnums. Other pistol cases work too, or any other round bushing that sits on the middle or so of the shoulder.
Click to expand...


What am I doing wrong???????

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Just kidding, the devil made me do it. :evil:
 
Well there i have it.
Shot case 3.636
Sized case 3.628
With the guage in place.

That would do it. .008 setting up the dies incorrect.

I will replace the brass after this last round. Half way through 200 now.
 
Below I'm measuring a fired case from my AR15 rifle, I then set the resizing die up for .003 shoulder bump.

The case springs back from the chamber walls and the case shoulder is not a snug fit in the chamber. Meaning the case is approximately .004 shorter than actual chamber headspace after .003 shoulder bump.

The general thumb rule for shoulder bump is .001 to .003 for a bolt action and .003 to .006 for a semi-auto, pump or lever action.

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One of the problems with drop in case gauges is a fired case may not drop all the way into the gauge. Meaning you have no idea of the shoulder location of a fired case.

Also, these type of gauges can vary in case body diameter, meaning they only measure shoulder location after sizing.

Below a Dillon .308 case gauge with a fired case in the gauge, and the case body diameter is preventing the case from dropping further into the gauge.

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And below the same fired case in a JP Enterprise .308 case gauge, this gauge is closer to minimum SAAMI body diameter. And why the case is sticking further out of this gauge. If a resized case and a loaded cartridge drops into this gauge it will chamber in any type rifle.

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Full. I tried the neck sizing only. But i think there isn't an perfect alignment of the bolt to chamber somewhere. Had to rotate the odd brass to get a nice chambering.
 
Ruger007 said:
Had my first one yesterday. Was a fouler shot.
Rem 700 308
Didn't even notice till i opened the bolt.


View attachment 399968

The batch (200) of Winchester brass is in it's 5th loading. I checked all the others with a piece of wire. Only found one that was even the slightest bit questionable.

No damage to face or gun.
Checked with my guages. It's not a head space issue with the gun.

Bought a headspace comparator now to set up dies better
Should be here tomorrow.

Could this have been a one off?
Click to expand...



Checking with Wire is I found the surest and fastest way. I do it all the time with hunting Rifle Shells never failed me in many years of reloading & commercial hunting dangerous Game.
The questionable ones I reserve for the Range.

Seems to me that one you missed or perhaps to frugal !

Cheers
 
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