Case head separation pics

I sometimes get the same thing on my brass. If you get a paper clip, straigten it out and bend the tip at a 90 degree angle and run it inside the case and feel for a groove at the base of the inside of the case. This groove is from the case stretching at the base. I am sure someone could explain this better than me.

Your chamber is cut a little oversize is all IMO.

Cases that aren't abused generally survive more than 4 loadings. It would be doubtful to have widespread problems unless you're pushing max load all the time.

What load did you shoot in those cases?

I have seen this happen to a friend shooting a 8x57 Mauser, a similarly configured case to a 308. He got some partial head separations & it turned out he was over resizing them. A combination of max chamber (common in ex military rifles) & a resizing die set right back as per makers instructions was setting his shoulders back a bit each time. Firing pin strike pushes case forward, combustion pressure grips case to chamber walls. Pressure continues to push unsupported head back against bolt face & stretches cases above the solid head. The groove you could feel is the thinned area where the stretching has occurred. The answer is to back the resizing die off till it just sizes the neck without setting the case shoulders back. Some smoke their cases to gauge this, others use maker pens.
Steve

Case head separation Photos

http://images.google.com/images?hl=en&q=Case+head+separation+&btnG=Search+Images&gbv=2 Go to Google, Images. Enter "case head separation" for photos. As said above, cases will only last as little as 3 firing with a maximum load. Oversizing(FLRS) will let the case stretch also.

http://images.google.com/imgres?imgurl=http://www.the-long-family.com/fireforming%25206-250AI_files/image003.jpg&imgrefurl=http://www.the-long-family.com/fireforming%25206-250AI.htm&h=402&w=600&sz=18&hl=en&start=1&usg=__dSdGm3fGaYyXPLNWbMqVXrc96K0=&tbnid=iDukAwwBHmg_UM:&tbnh=90&tbnw=135&prev=/images%3Fq%3DCase%2Bhead%2Bseparation%26gbv%3D2%26hl%3Den%26safe%3Doff%26sa%3DG good photos here.

Full Length Sizing Die Adjustment for a Bolt Action Rifle

Set your flrs die this way to avoid oversizing the brass in a bolt action rifle. Make a shim from a soda can. Thickness is about .004" Put a hole in the center of shim for the decaping pin. Place the shim between the shell holder and flrs die when setting the flrs die adjustment in the press. Try 3 cases flrs this way to see if they will chamber in your bolt action rifle. If they chamber, load and shoot. This works well with bottle neck type cases. If the sized cases do not chamber easly, forget the shim. Your rifles headspace is on the small side. If your chamber is large in diameter/width, this will not help.

Aah me...Now Walkalong has dyslexia. What else do I have to look forward to when I get old?

I've loaded some pretty nasty loads in .30-06 over the years and have never seen any signs of case head seperation. If you haven't been loading hot and you are using quality cases and procedures what you may be seeing is just the die making that shinny ring at the junction of the case web and case wall when the die returns the case to proper size...[Now you watch...I'll start seeing it...You wait and see. Murphy and I are good friends]

After first firing, neck size to last longer.

I highly recommend using a case gage (or better yet, case comparitor) with any FL or SB die. Otherwise, you're pretty much setting it blindly. Overworking brass will make a huge impact on case life.

That shiny ring is what is called a "stretch ring" caused by excess headspace.

As others have said, your excess headspace problem is being caused by pushing the shoulder back too far with your current sizing die adjustment.

Back off your sizing die until you can fee resistance when the bolt closes on a sized empty case, and you should cure the problem.

Yeh...Forgot about that. What rcmodel said...

A very handy tool to have is the Hornady (used to be Stoney Point) headspace checker that attaches to calipers. Measure distance between the case head and the index point on the shoulder of the case then set the FL die to size the case to 0.002-3 inch less than that. Cases FL sized with just enough shoulder bump to give easy chambering should last as long as neck sized cases unless the chamber is way oversized. If the chamber is oversized in diameter the cases will be very bulged after firing, then neck sizing is the only way to get reasonable case life. In a normal sized chamber properly FL sized cases should last for many firings unless they're loaded too hot.

If it's a model 88 winchester, I can tell you that the chamber has max headspace. I had one and had it checked at a gunsmith and the chamber was not a no-go but field. this means that it is at the very maximum that is still considered safe. I bet you get flatened primers as well. do as they suggest and just try neck resizing even though it's a lever action. If you have read about sizing for lever actions you probely are useing a small base die which will make it even worse. Tru a standard die and full leth resize the case and if that dosn't help keep backing off the die until your good.

Get out your trusty hacksaw and split one of the cases in question to have a look-see. It shouldn't be hard to tell if you are seing the warning signs of case separation. As mentioned above you may have headspace issues.