A couple of pressure questions

[Ol` Joe]

Some loads use powders that fill the case before enough powder is used to produce top pressures. There are other loads that may not be uniform enough in pressure highs and lows to allow the use of loads that average peak SAAMI pressure. Pressure isn`t the same in every load and there can be very large swings between high and low in some cases. The listed figures are averages of the labs findings and there may have been a peak recorded that went 5K psi higher that you don`t see in the data.

For your question on building a firearm to take greater pressure then presently done , remember the whole is only as strong as the weakest link. The case is much weaker then the steel action now used. Stronger guns may be possible but if you experiance case failure it won`t help.