Cartridge Case Head Separation

Cartridge Case Head Separation

This is a problem that can arise with multiple reloadings.  I have been watching out for it with my 223 Rem cases.  I figured the normally robust little cases would develop this sooner or later because I have been full-length resizing them and they have seen a few hot loads as well.

This situation has come about because of the number of review rifles in 223 Rem that I have worked with over the last few years.  It is nigh on impossible to keep all the cases separated and, in the end, it was easier just to full-length resize every case.

What you need to look out for is the bright, thin line around the case about 5mm (1/4 inch) above the extraction groove on the case head.  That fine, bright line is the tell-tale sign of the case wall thinning at that location.  The photo shows three stages of development of this problem, from the faintest line to a shell that has cut right through nearly all the way around (it was a minor miracle that this shell did not separate!).

You can make a highly effective tool to detect that.  All it requires is a paper clip, preferably one of the larger size variety.  I actually made mine from a short length of nickel wire, after my paper clip tool went rusty.  I also filed a little chisel edge on the point in order to pick up the faintest beginnings of thinning and crack development.  However, that is nit really necessary; the blunt end of a bent paperclip will work fine.

It takes no more than a second to check a cartridge case.  Having inserted the bent probe into the case I move it in and out three or four times as I rotate the case in my fingers.  This effectively checks the entire inner surface of the shell.  Any cases that have visible and/or probe detected thinning go into the bin.  There is no fixing them.  The last thing you want is a full separation of the case.  When that happens, the front part of the shell remains wedged tightly in the chamber while the extractor yanks out the separated base.

This is hard enough to fix at home in the workshop, let alone out in the bush on a hunt.  The key lesson here is to always clean and inspect your fired cases before reloading.