Case head separation?

[BourgeoisKe1]

Good afternoon all,
Hopefully someone can help me out a little. I recently had to make a barrel adjustment on a Savage Axis in 22-250. After shooting it I noticed some slight deformation in the brass. Can anyone tell me if this is the begining of some case head seperation; possibly caused by too much headspace.

https://drive.google.com/file/d/0B1-27oqLzVi2eXpITmZmOU9uYjg/view?usp=drivesdk

https://drive.google.com/file/d/0B1-27oqLzVi2aWZQQnFUOUpOTUE/view?usp=drivesdk

 

[BrotherRockeye]

Check the inside with a pick or paper clip to see if the case has stretched and thinned
Could just be resizing marks.

good read here:
https://www.canadiangunnutz.com/forum/showthread.php/1557878-Odd-Occurrence-Help!

 

[hometownhero]

No it is not.

This is what it will look like

 

[Chrossphyre]

Better yet, cut one open and check the wall thickness at the bulge as compared to the rest of the case wall.

 

[BourgeoisKe1]

Thanks for the replies. I will check ot out. Might just be the shape of the chamber I guess. But i will add that these were factory loads, only one firing. And this happened to all 19 that I shot today, which did not have any deformations before firing.

 

[kward]

why did you have to do an adjustment???

 

[Longwalker]

looks like normal case expansion to me.

 

[yomomma]

looks like normal case expansion to me.

Yup

 

[bigedp51]

Below both factory loaded .303 British cases were fired in the same Enfield rifle. The differance is the Prvi case has a larger base diameter and the HXP case hase a smaller base diameter.

Neither case stretched or thinned when fired, the HXP case had further to expand to contact the chamber walls. Most American made cases tend to be at the minimum SAAMI base diameter and do what you have pictured in your photos.

The photo posted by hometownhero shows you that most case head separations occur "above" where the case expander to contact the chamber.

Below a Winchester .303 British case on the right that was full length resized three times and split "above" the maximum area of expansion where the brass is thinner.

Below same case as above with different angle and lighting.

Bottom line, what you are seeing is normal and again the smaller the base diameter the more pronounced it will be.

 

[BourgeoisKe1]

why did you have to do an adjustment???

I had the barreled action Cerakoted by an "Amateur" who took the barrel off, or at least tried to, and did not reinstall it properly. It was out about two full turns.

 

[BourgeoisKe1]

Thank you to everyone who replied and helped me out and gave me a good lesson on this matter.

 

[bigedp51]

If you would have had a Hornady cartridge case headspace gauge you would have found the problem much sooner.

Below a fired 5.56 from my AR15 "before" sizing and with this same gauge I adjusted the sizing die for .003 shoulder bump.

Below a Colt Field gauge 1.4736

Below the Field gauge in my adjusted/calibrated Hornady gauge 1.4735

The problem with cases gauges like the Wilson type case gauge is a fired case many times will not fit until the case has been resized. Meaning you never know the "fired" length of the case before sizing.

 

[BourgeoisKe1]

Thanks to all that replied. Very helpful and informative.

 

[GMC403]

 

[bigedp51]

When I started collecting the Enfield rifle I bought a RCBS $100.00 bent paper clip.
No feeling for thinning with a bent paper clip or wire it will measure case stretching and thinning in thousandths of an inch.

RCBS Case Master Concentricity Gaging Tool
https://www.midwayusa.com/product/310955/rcbs-case-master-concentricity-gaging-tool