Fiocchi loads some of the hottest factory ammo on the market and generally has a good reputation. I might suspect your recoil spring is too stiff or possibly the slide lock lever is worn on the edge that is supposed to hold against the slide cut out. Also check the slide for rounding over there.Brett Joshua said:(I also posted this in the Ammo section)
The last time I shot Fiocchis I had a different problem - after ejecting the spent mag and loading a fresh one, the slide automatically slammed shut and chambered the first round. The range master told me this was because the ammo did not create enough recoil to lock the slide back completely after firing the last round.
Are Fiocchi's no good? Or is there a problem with my 1911? (Colt Series 80)
The other problems you describe make me suspect a weak mag spring because they are occurring near the last rounds where the mag spring is extended and giving minimum spring force.