SmallCaliberCentral

Rick in Oregon:
You "respectfilly disagree"? At least we're not throwing rocks at each other. I've had a few overloads myself. The only brass that I've ever seen a case head seperation on was well used and fired many times. Never seen it happen on new brass. That's why folks fireform with false shoulders to blow out the cases. In my case, most are close to chamber length and jammed bullets keep the brass tight on the bolt head along with lots of neck tension.
Short cases havn't been too much of a problem for me because all my loads are built with the bullets stuffed .010 "into" the lands. That keeps the case head back against the bolt face.
And all my barrels are ordered with short throats just for that reason. Once the brass is fireformed, headspace (short brass) isn't a problem. Overloads do crop up at times.

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?

I did some testing over the weekend and it appears I owe everybody who said my load was too hot an apology. I measured some of the Nosler cases before loading and they were all 1.830" or 1.831", at the minimum length. On firing, half the primers blew out. When I measured those cases and they were all below 1.820", so it would appear my load is too hot for the cases and it is not a manufacturing defect. That being said, I am still very disappointed in the performance of Nosler brass. Nosler cases are advertised as premium brass and you pay a premium price, yet in my experience they don't match the performance of supposedly inferior brass like Winchester, Remington or Hornady. I have used those for years with no problems using the exact same load that the Noslers can't handle, load data that I got from the link on this very site. I will be returning the unopened brass to Brownells for a refund and for the rest I'll try and find a weaker load that Nosler brass can tolerate. I just find it hard to believe
that the "Cadillac" of rifle brass is so much more fragile than the economy stuff. If anything I would have expected the Noslers to be much stronger.

By premium; to me that means more consistent and maybe a tad thicker.

Take the WIN/REM brass you have, completely a WIN/REM case and a NOSLER case with water or other consistent material and then way the them. NOTE: make sure they are full, no voids or air pockets! If they vary [and for a small case like the 204, it doesn't take much] there is one of the first clues. Folks who use a lot of military brass run into this quite often, especially in the 30 caliber rounds because the brass is thicker.

HTH,

Apology accepted.

But I think you're still missing the point. It's not brass quality we're talkin' here, it's actually physics. I would opine that you've run into internal volume differences, plus using a load "from the internet", this site or otherwise. Did the load you 'duplicated' from other than published book data contain Nosler brass as the key component? I'm betting not. One of the very first things I learned when starting handloading was this primary rule. It appears not all of us have.

Again...........if you change ANY specific ingredient of a given published or previously used load, it's best (smart) to reduce and work up again to be sure it's safe in YOUR rifle. You may also find that a reduced/worked up load using the same components may give you all the speed or accuracy you're after.

Nosler brass is indeed premium brass. But even preminum products are meaningless if used improperly, and will therefore not reach their full intended potential.

Very well stated RIO. Could not have said it better!

As soon as you put the SAME amount of powder into a case with a smaller internal volume (Nosler) than your old brass (RP, WW), you no longer had an IDENTICAL load. That Nosler brass was subjected to way more pressure, even though it was your usual charge in weight. As Rick said, the strength of the Nosler brass is not the issue at all. It's all about pressure, pressure, pressure. You lost some spendy brass but, you could have lost way more than that.

I get the point Rick. I made assumptions I shouldn't have regarding consistency between different manufacturers. It wont happen again.

And loosing a few pieces of "premimum" brass is nothing compared to blowing up or damaging your gun or worse yet, personel injury. Sounds like you got off pretty cheap!
Now, take the info that you've learned from this experience, put it on a sticky note and slap it on your forehead (like I do ) so you won't make that mistake again. (some times I can't see for all the stickys!)
Just a little more info to put away so you don't run into that same thing again. All or most of us have been there, done that and have learned a lesson from our experiences.
For me, I'am still learning, no matter how old I get.
Good bunch of guy here with lots of experience and I plan to keep an open mind about what they say and have done. Still learning at my age!

Nor Cal Mikie wrote:And loosing a few pieces of "premimum" brass is nothing compared to blowing up or damaging your gun or worse yet, personel injury. Sounds like you got off pretty cheap!

You're right Mikie, the rifle is fine, I'm fine - nothing damaged but a little brass and my pride. But I have learned my lesson. NEVER EVER assume anything when it comes to reloading, no matter how trivial you think the change might be. It might not turn out like you expected.