Maximum Pressure for the 300 Win Mag:
CIP = 62,000 psi (4,300 bar)
SAAMI = 64,000 psi (4,400 bar)
Using my load data in QuickLoad, I get 62442 psi (4305 bar), so I'm just over CIP, and under SAAMI (screenshot attached).
The only reason that the Pmax is given in red (and message DO NOT USE THIS LOAD) is because the Pmax (MAP) threshold is set to 62336 by default under the cartridge selection. If you change it to 64000 psi, then it changes to purple, and the "DO NOT USE THIS LOAD" message disappears.
This just an Application with thresholds and messages set based on predetermined metrics, NOT the holy grail of reloading. If QL says my loads are at Max Pressure, and my cases show no signs of excess pressure, I don't see a problem.
The published data from Somchem uses PMP Cartridges with internal volume of as low as 85gr H2O. I tested this myself, I have 100 PMP cases. Very durable due to thick sidewalls, but also very limited and varying internal capacities.
I attached the Somchem Data for the 300 win mag. You can run these different loads through QL, and will quickly see 60 000 psi is not uncommon, I found as high as 63 000 psi and this is Factory Ammo, made according to pressure specs for the 300 win mag.
So, if my 62442 psi (442 psi over CIP spec) is a problem, then:
If you're buying factory ammo, you have no way of actually knowing how hot that load is, thus shooting your favorite factory ammo for many years might blow up your rifle like that extreme case with the springfield because it was loaded at Pmax of your rifle???
Nah, doesn't make sense.
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