Thread: Case head separation imminent

Originally Posted by yogi

What a timely post to come back home to after a hunting trip at the weekend!
Attachment 209760

Have reloaded for years without to many issues but at the weekend i fired a shot and extracted the head of the cartridge only.
The rest was jammed in the chamber, which was not a happy time with a bunch of tahr standing there looking at us and no functioning rifle!
Trudged a long way back to the hut and managed to pull the stuck case with a pull through.

Back up the hill and fired two more shots and was horrified to find cracks in the next two also.

The brass has only been fired two times, no head space issue in the rifle, load rechecked on the scales and dies set as per instructions also.

Ok, so from reading through the rest of this post , it seems the dies are also not set up properly and will be oversizing the case causing a headspace problem that is allowing the case to much expansion when firing??
The dies will be pushing the shoulder down to much?

Does this also mean all my resized brass will be ruined?

Rifle is a 7mm rem mag

Never had the issues before

Greetings,
Maybe. You can check with a bent paper clip feeling for a groove on the inside of the case. If you feel a groove bin it. Sizing belted cases is fraught with problems. You could (and should) back out the die so it moves the shoulder back about 0.002" but this can allow another problem. A bulge can develop right in front of the belt which makes the case chamber hard. There is a kit to remove the bulge or you can use a stripped 300 Win Mag die to do this. PM me if you want more on this.
The belt on the 7mm Rem Mag is a fashion accessory and serves no useful purpose. There is excess headspace in your rifle but probably within manufacturing tolerances and setting the sizing die down hard on the shell holder as per instructions can result in head separations in many rifles for belted cases. Case construction can be a factor.
Regards Grandpamac.