I've got a handful of the wooden bullet Kropatechek rounds as well.
The rifle long gone, wish I still had it.

Some of the wooden bullet rounds used by some countrys have the bullets made as a hollow projectile. This to better ensure the bullet breaks up on it's trip down the bore and upon it's exit at the muzzle.
The Steyr rifling is very deep and likely helped slice the bullet into pieces if that was the intension.

The wooden bullet form likely needed so the rifle would operate as a repeated for training purposes. A simple crimped brass blank not always a workable round in all mechanisms.

I seem to recall reading that the Dutch used a hollow wooden bullet as a training/blank round in their 1895 Mannlicher rifle&carbine as well.

FA making ammo for Portugal in 1904?....hey why not. It's money and it keeps the machines and employees busy