Kingarthurhk, I am sure that all of the aforementioned guns have been tested with strain gauges attached to figure out how much pressure will cause them to fail.
Assuredly, none of them are at the SAAMI pressure spec for any given cartridge they are chambered in. They have to have to be able to handle higher pressures, otherwise they would not be able to survive proof testing in countries that do proof testing.
Besides that, I believe SAAMI specifications allow 1 in 1000 of a given lot to be high or low.
Quando Omni Flunkus Moritati