A customer sent us his upper after a minor mishap during load development.  While coming up with a good load for the 300 gr Barnes X Spitzer, he got a little impatient (he admitted to it) and loaded a bit on the adventurous side.  The round fired but failed to extract and he could not get the bolt open.  We got it open with a little "encouragement" and this is what the case looked like

Note the "belt" on the case as a result of the over pressure


Note the totally flat primer.  The headstamp is barely legible and you can see where brass was forced into both the ejector and extractor openings.


Now, since we came out with the .458 SOCOM, several people including highly respected industry professionals have commented that we were foolish to choose the rim size we did AND neck the case down.  It was stated that the bolt would not hold up to the bolt thrust, however, this load produced 30% overpressure and the bolt is just fine.  Also, note that the case held up and did not fail or collapse, as we were told might happen as well.  By choosing the larger rim, enough material remains at the base of the case to prevent that from happening.  So despite all the people saying we were wrong, I think the proof is in the pudding ....

"gun industry professionals"................Marty, where do you find those?  ;-)

Tony Rumore
Tromix Corp

Come on Tony, there are tens of thousands of "gun industry professionals" on this board, and an equal amount of of ex-navy seals, rangers ...

Quoted: ...an equal amount of of ex-navy seals, rangers ...

Pfft....I was a doorgunner on the.....

Oh nevermind.

Hey a belted magnum

How adventurous was this "excursion". What did he load it to?

DDDDDDaaaammmnnnnn.  I have loaded what I thought was HOT HOT ammo for the 458, but never like that!  WOW!

Nice to know that even if we mess up, Marty put a large safety margin into the design.  Thanks Marty!

Tom  

Quoted: How adventurous was this "excursion". What did he load it to?

The load was 30% overpressure.  Given that we state that 35000 is max, his load came in around 47,000.  That one was not near as bad as one that Tony reported where Win 296 was inadvertently replaced with Win 231 or something like that.  That load was calculated to be close to 85,000 IIRC

Quoted: Now, since we came out with the .458 SOCOM, several people including highly respected industry professionals have commented that we were foolish to choose the rim size we did AND neck the case down.  It was stated that the bolt would not hold up to the bolt thrust, however, this load produced 30% overpressure and the bolt is just fine.  Also, note that the case held up and did not fail or collapse, as we were told might happen as well.  By choosing the larger rim, enough material remains at the base of the case to prevent that from happening.  So despite all the people saying we were wrong, I think the proof is in the pudding ....

F' the naysayers...

I have had a few minor excursions into the wrong side of the pressure line, and I definately had slight marks from the extracter and ejector on the case, that went hand in hand with enlargened primer pockets.  I have found pressure signs with the 458 to line right up with every other cartridge that I have worked on.  I am no cool aide drinker, but the MP stamp on my Colt 458 modified bolt sure gives me warm fuzzies......

Craig