I don't doubt in the least how the author of the Wooden Bullets article came across them but I think he came to the wrong conclusion about their purpose. As someone else posted, it was common in Europe to use wooden bulleted cartridges for blank or grenade launching rounds. In the US the cartridge casings would be sealed w/a rosette crimp on the case mouth for blanks or grenade launching. Interestingly the French used some rifle grenades which were designed to be launched w/ ball cartridges. When my Dad was in the US Navy he was told the tale that the Japanese in the Pacific war would pull the bullet from a rifle cartridge & replace it w/ bamboo. The bamboo bulleted round would be used to wound one Allied soldier forcing others to come under fire in their attempt to assist the wounded man.
Yep the wooden bullets are used only as blank rounds for drill purposes and for the rifle grenades. The aluminium was used to save the lead for other things and to make it lighter. These rounds were used as standard infantery rounds too.
Thanks for remembering me on that! I forgot this fact, you´re right it was used as short range training ounds since the austrians used it with their Kropatschek rifles.