Thread: Case separation, rough chamber, brittle cases?

Originally Posted by grandpamac

Greetings again,
From the photograph the edge of the breal looks like classic head separation from excess head space. The crack starts from a groove on the inside of the case and progresses to the outside. This usually takes more than one shot, mostly several. For this reason I wonder if you are absolutely sure that the cartridges are not reloads. If they are factory new then the headspace is likely to be grosly excessive or the rifle is not locking up securely. In any case best not fire it until it is sorted.
GPM.

All but one of the damaged cases is Belmont ammo, so could well be reloaded. The other case is a PMC, we fired a dozen of them with no cracking or marks showing.

I'd guess Belmont would take these (remanufactured) cases back to absolute minimum SAAMI to guarantee chambering in all firearms but that shouldn't produce a case separation in a single firing unless the headspace is -grossly- excessive as GPM said.

I too look with interest as to the gunsmith's opinion.

Originally Posted by Tentman

See if the GS will let you watch as he checks headspace. Its done a bit different on a break action. He should first use a feeler guage to measure the "gap" between the breech face and barrel, then use the headspace guages. If he/she doesnt do this I'd be getting another opinion. Cheers

Be interesting to get an actual headspace measurement, i.e. the length of the chamber in the barrel and not relative to the action face. Possibly the case is sitting on the extractor when chambered, and it's held there firmly enough to allow the primer to be set off by the firing pin when in reality the case should be sitting on it's shoulder and the extractor not doing anything until it's time to pop the fired case out. Needs a good look at before I'd fire it with my face next to it...