Case Failure

[bcmulie]

I recently used some cases from a major manufacturer and had two of the cases separate at the base of the neck when fired(the neck entirely separated from the rest of the cartridge). The brass had been fired once previously with a load that I have been using for years without problems. When I attempted to pull the bullets from the remaining cases, the necks pulled off with minimal effort. I sent one of the cases I'd fired a second time to the manufacturer, who advised that there was a "stress fracture" but that they couldn't determine the cause. Has anyone else had a problem like this, and can anyone tell me what the possible causes of a stress fracture are?

 

[rost495]

FWIW the brass has to be either faulty, excess headspace though thats normally a seperation close to the head, or very brittle. Brittle can come from loading too much or not being annealed correctly.

Or from sitting loaded for years through heat and cold cycles where the brass and copper have different expansion ratios and hence the work hardening. I used to get split necks from that until I started storing all my loaded ammo in the house under climate control.

Jeff

 

[bcmulie]

Thanks for the info Jeff. I can't see that it's a headspace problem as I have fired literally hundreds of rounds through this rifle without any problems. I bought the brass new this June, so I'd have to rule out the storage problem. My view is that the brass was faulty, either because of some problem with the annealing process or otherwise.

Alan