Daryl, it'd be nice if ammo makers would give us pressures for their loads because then, as you say, we'd know and could decide for ourselves. But even the Brits don't do that with their shells, except in a very general fashion:
"Please note that these cartridges are suitable for use in: Guns with a chamber length of 2 1/2" or longer, nitro proofed to a service pressure of 3 tons per square inch (850 kg per square km)." That's right off a box of Kent Gamebore Pure Gold 12ga shells, 2 1/2". At least it tells us they don't exceed current CIP service pressure standards.
