I'm not sure these grooves are related to the driving band. There should be feathering under the copper driving band to prevent the band from rotating on the shell. If we are oriented correctly, the groves (in my opinion) run around the shell. Such an arrangement as seen in the pics would easily allow the driving band to rotate. If I recall correctly there were two semi-fixed German shells 152mm and 75mm that might have these bands below the driving band. Again, for common reference, I would say the ogive is above the driving band.
Just a thought!