Tokimini wrote:You are all right, my bad. I got a little complacent I guess, but I think I might have found the problem. I measured the case length on the ones with the blown out primers and every one was 1.818" or shorter. Everything longer than that was fine. I checked the SAAMI specs and the case length for the 204 is listed as 1.850 - .020. Does that mean the minimum case length is 1.830? It seems more than coincidental that every round with a case length less than 1.820" had the primer blow out. I have a set of Go, No Go gauges and the headspace checks out OK.
I would suggest your short overall cases all blowing out is not the cause of failure but a result of the failure that occurred. Measuring them after the fact only tells you what happened after the fact. You have no idea what the length variation was before.
Overall length of the case will not produce effects like these. What your seeing is brass that has been fired at higher pressures than the other cases. Being new (small) brass it has expanded more to fill the chamber than the other cases. That expansion has to draw brass from somewhere. Only one direction fully expanded brass can pull brass from, backwards.
Bottom line, that brass is obviously showing some Extreme over pressure. Rather obvious with the primers gone right
Your right to toss them, they're trash. But I can't see how volume is enough to cause that drastic an effect. Either your pet load was already over pressure or you messed something up or something else has changed.
Nosler has been some of the best brass I've ever used in 204, yes it does come short (pretrimmed)but the headspace has always been good. Always possible they put out a batch with soft heads. Stuff happens.
With the gun industry running full speed we shooters always need to be more diligent in our pursuits. Simple numbers dictate mistakes will slip by the companies and it's up to us to catch them.
Good luck figuring it out. I would go through the headspace of any unforced brass and see if there's any large discrepancies.
What gun?