Carcano/Cable,
In my humble opinion, the 24/24x25-35 drilling would have been primarily used to hunt Reh deer and not as a "Schonzeitdrilling", although it could certainly be used during the "Schoenzeit", with or without the low power cartridges made especially for the season. Since Rehwild is classified as Niederwild, I suppose "Niederwilddrilling" would not be a technically incorrect term, but I would consider it a drilling for use in a Niederwild Revier since it would be lawful for some Hochwild.
Mike