Old Beretta Model 90 .32

I posted some questions about an old Beretta Model 90 .32 that I picked up recently. Long story short...the action was extremely gummed up but the bore looked almost brand new. The everything mechanical felt nice and tight. After a lot of cleaning, it felt like a new Walther.
Problem is, It seems to want to jam an awfully lot. I have ordered a 2 new magazines for it as I'm hoping that perhaps the clip that came with it was had 7 rounds in it for the last 35 years that it sat in a cardboard box in someone's garage.

Aside from a funky old magazine, what else might cause a jamming problem like this. It's an extremely simple mechanism with a single large spring around the barrel.

I'm using regular old .32-71 gr ammunition and the gun is as clean as clean can be.

I'd be interested in opinions on this.

Maybe what we have is a 40 year old pistol that isn't yet broken in. Not enough rounds have gone through it. That would be pretty funny but entirely possible.