Disclaimer: if you ever do a similar find, NEVER touch it: shells, hand grenades and shell fuses are still dangerous 100 years after the war. Your life is more than important than your collection.
These Austrian shells were discovered near a cavern in the Tonale Pass region. They’ve been measured and their diameter (70 mm, if the measure is right) that they were used by the obsolete 7 cm Gebirgsgeschütz M 99, which was a mountain gun used by Austria-Hungary during World War I. It had a bronze barrel and only a spring-loaded spade to absorb the recoil forces and it had to be relaid after every shot.
The precise position of these shells has been taken with a GPS and communicated to the local authorities.