Unusual Copper Buildup?
I've used Fiocchi ammo as well; in my experience it was accurate, reliable, and a tad hot.
One odd thing I noticed is that their 9x19mm rounds caused quite a bit of copper buildup in cmy onventionally-rifled barrels. It was much more pronounced than I've seen with Federal, Winchester, Speer, or other commercial ammo,
I didn't observe this with their .40's, but their .40's have a brass-colored jacket and are "Made in Hungary" versus the 9mm's copper-colored jacket and "Made in Italy" tag. (If memory serves.)
As a result, I tend to steer clear of their 9mms, unless I feel like spending more "quality time" with copper solvent and a brush.
-PH