I don't even own a Beretta, but almost every one I've fired had some kind of quirk with feeding, properly oiled or not. I usually have to pull out the magazine spring and give it a stretchy-stretchy to deal with the failure to feed. You should see the horrified expressions on the owners' faces when I do that, especially the LEOs. But it always works.
I picked this trick up from an FFL dealer at the range. Perhaps it's not the correct approach but perhaps the effing piece should not be so sensitive either.
The anemic performance of the 9MM NATO FMJ round, however, is a different story.