Thanks. This is the one I have:
It looks like maybe the adjustment is the two screws at the top? If I make them go up, it looks like it's longer until the screw hits and the plunger is going down more. The opening for the cork is plastic and unscrews but that's probably just its assembly. I will practice some more...but there were only 30 corks in the bag to start with! Better practice vs lousing up the whole batch.
You've listed a lot of wine...does corking ever get easier?