Originally Fiocchi imported their ammo from the Italy plant. They built a USA plant in the early 90s. The Italian stuff was the BEST around. Shot MANY a case on sporting clays and live pigeon shoots. Their US plant uses domestic components and is no better or worse than any other USA made shotgun shells.
The last 5-6 years I've been shooting Baschieri and Pellagri shotgun shells. Another imported Italian made shell.
Powder is the difference. The Italian shotgun powder is a flake powder. Hotter, cleaner and faster.