The Lancaster Model A (Wristbreaker) & Purdey are true "self openers". The Holland is an assisted opener but they like to use the term "self opening" when describing their action. The reality is...the Holland is only a self opener if it hasn't been fired

. Fire the Holland action, especially both locks and see how it "self opens"...it doesn't. What it does is "pops" open but does not pop open enough to cock the action or eject the hulls...the coil spring under the barrels does not have the strength to do both of these jobs. It helps if the H&H is equipped with longer, heavier barrels to aid in the force of the drop.
Both the Lancaster and the Purdey vigorously spring open whether cocked or uncocked, the Lancaster cocks the locks and ejects the hulls without any effort from the person using the gun other than pushing the top lever over to the right, the Purdey cocks on closing, but the action has enough force to eject spent hulls.
We've gone over this before....a topic that seems to come up every few months or so.
Dustin