Too Much Pressure??

[strobes]

First I'd like to make it clear - I'm new to Whisper, but have experience loading in supersonic for BR target and subsonic for fun in .308
So I use QuickLoad 3.2 to develop loads and my experience is that this software is very good.
I'm finishing my first custom rifle and wanted to make some supersonic loads to form brass.
To my surprise all published supersonic loads producing significant overpressure that is very unsafe according to QuickLoad.
So my question is what am I missing?
here is QC screen
http://www.freeimagehosting.net/uploads/5e5d0d942c.jpg

[snipecatcher]

With VV-N110, which looks to be very similar to H110, I can't get any pressure signs with a 125 gr. bullet, period. The most powder I've felt comfortable stuffing in there is 18 grains, and even then, it gets compressed a bit by the bullet. This is in a Savage action with a Shilen barrel. I may try some 150 grain bullets one of these days, but I still think it would be hard to rupture a case like that, unless there was something already wrong with the case. Personally, I'd reduce the charge a bit and work up from there just to be safe.
-Dan

[CKOD]

Originally Posted by strobes

First I'd like to make it clear - I'm new to Whisper, but have experience loading in supersonic for BR target and subsonic for fun in .308
So I use QuickLoad 3.2 to develop loads and my experience is that this software is very good.
I'm finishing my first custom rifle and wanted to make some supersonic loads to form brass.
To my surprise all published supersonic loads producing significant overpressure that is very unsafe according to QuickLoad.
So my question is what am I missing?
here is QC screen
http://www.freeimagehosting.net/uploads/5e5d0d942c.jpg

I'm no expert on the subject either, but 55kPSI is within the .223rem SAAMI specs, (well at the max, but within the 5.56 specs) so if youre using cut down .223 brass, I'd see no reason the brass couldnt handle the pressure. The chamber/head area on the rifle is the same as .223, and unless you have a thin spot in the barrel from the bore being .308 instead of .224. So other then a thin spot in the barrel profiles I dont see why 55k PSI would be unreasonable.

I wonder who speced the max pressure for .300-221 in quickload.