Well, well, shades of times long past...
I bought one nib just like it in Dublin, Ga. in the summer of 1966, for $35.00.
Mine never met a full magazine it liked, and here we are 44 years later, I still own it, and it STILL won't shoot a full magazine without a burp of some kind.
But, perhaps I just got the bad one..
I think any quality brand of 25acp ammo will work just fine in the old Galesi, I would suggest fmj's, easily found at Wally World or your local gun shop.
Good luck to ya..