Incipient case head separation? - Thanks for your replies.

[Eric]

I want to know if my cases are approaching incipient case head separation.  Although I load powder levels well below maximum my cases have a small ridge about 0.2 inches above the web (even after the first firing).  I can see light marks on the case (from the chamber) everywhere on the case except in the first 0.2 inches above the web.  The case diameter is slightly less in the first 0.2 inches - I can feel it with my fingers.  I think that the head space is correct.  I am loading for a Contender (30 Herrett) and I size so that the gun just closes with a light snap and then I only neck size on later reloads.  I have checked the inside of the cases for a ridge but have never found any.  I have cut a case down to get a better look.  The inside looks normal.  Is this incipient case head separation?

[jgalar]

I would say no. I get the same thing with British Enfields.  The chamber is most likely a little screwy and you brass is forming to it. As long as you are neck sizing and the brass doesn't need constant trimming then your case isn't thinning in that area.

[Duffy]

Eric,
If you are not feeling a ridge inside your cases are ok. That bulge or lack of bulge just ahead of the rim is normal and it is the thickest part of the case. If you are getting seperation it will be a little bit ahead of that non bulged area. It took me awhile to notice it also but once you see it it's easy to spot. It will show up as a thin line or crack that is lighter, more yellow than the rest of the brass and it is sometimes not all the way around. Your chamber may be a bit large and that is causing the bulge ahead of the web area.

[New Hampshire]

Another indication of case head seperation is a bright ring will appear in the area where the case will tear (if it hadnt already.)
Brian M.

[jgalar]

Eric I/we don't know how long you have been reloading - could the ring you see just be the area of the case that the sizing die isn't resizing?

[Lone Star]

If the cases are sized as described, then the chance of case head separations is virtually non-existent. The Herretts along with the .35 Remington have a long history of case head separations due to incorrect resizing techniques, but with the die set up as described the headspace is perfect and there is nowhere for the case head to move - so no case stretching just above the web.  

This is what the reloader is seeing, the case expanding to full the chamber above the solid web of the case.  Some .30-30 brass is a bit undersized and some Herrett chambers were a bit oversized, resulting in fired cases with a pronounced diameter increase above the web with hot loads.  Nothing to worry about...

[Nightrain52]

Maybe you have already tried this but take a wire coat hanger or something similar about 6 inches long and on one end bend it at a 90 degree angle then trim bend to fit down the case throat. Put to the bottom of the case and where the angled end is rubbing against the side of the case inside work up and down in the lower 1/4 of the case and if it is getting ready to seperate you should be able to feel it with the wire. Not very scientific but it works.

[Darrell Davis]

Hey there Eric,

Nighttrain52 gave you a good tip about using a prob to check the inside of the case.

However, I find a paper clip is easier to use. Strighten it out, bend about a 1/4" at 090% to the main length and then take a small file and sharpen the end of the short leg.

As he said, by moving the short leg up and down inside the case you will feel any groove which may be forming.

Another tip is to keep track of your case length. If the cases are "growing" in length, you will at some point end up with cases which are starting to separate. When this happens, you may see the bright ring spoken of in some of the posts.

When cases grow, the "growth,"  or streaching comes from just ahead of the head, which is where the bright ring and partial or complete seperation will occur.

Keep em coming! :wink: