Complex sentence: The Otobreda 76 mm gun is a naval artillery piece built by the Italian defence conglomerate of Otobreda, developed originally from the Oto Melara 76/62mm Allargato, which was bigger, heavier and had a slower rate of fire.
Split into simpler sentences: The Otobreda 76 mm gun is a naval artillery piece built by the Italian defence conglomerate Otobreda. It is based on the Oto Melara 76/62mm Allargato, which was bigger, heavier, and had a slower rate of fire.