Every Beretta I've ever handled had a failure to feed during shooting practice. I fixed them all by giving the magazine spring a little "stretchy-stretchy" (thx whoever showed me that, I can't recall now). Seemed kind of weird to me, what's the point of a ductile spring? I suspect gov't requirements at the root of some conflicted engineering decision...
As to fmj only.
Fmj FP WS used in .32 Acp side arms to makrpe them s little less anemic. Might help with the 9para.