The replies from Ted and Stan were the only ones that came even close to answering the OP's question.
Specialty ammo loaded to lower pressures seems to almost always be more expensive than standard SAAMI spec ammo. So it would seem to benefit ammo makers financially to disclose pressure data for each lot they produce. Archaic terms such as Dram Equivalent mean little to the average shooter. There is no question they test their ammo and have that data. There is no question that they do more testing anytime they change powder, primers, or other components, just out of product liability concerns.
Or maybe they don't give us a thought, since the segment of the market that wants lower pressure ammo isn't large enough to get their attention. And maybe that situation could change if enough of us requested it from the source... instead of asking people who just don't know.
