As I recall, the SAAMI limits reflect an assumed coefficient of variation of 4%, or that the standard deviation is 4% of the average. For the mythical 60K psi Maximum Average Pressure, this would mean that roughly one round out of a hundred might exceed 67K psi. I know of no published limits on the maximum allowed standard deviation. You can be assured that if the observed SD is too high, the test will be refired several times.
KenO
