I stopped counting how many flawless rounds out of my first Pico at 2500. That was quite some time ago and I shoot pocket guns almost weekly. The other Pico the same at 1500. I have 12 magazines. As mentioned above I always load to full capacity and let them SET for a few days. I then load the mags up minus one and shoot them for a few weeks. Never had a problem yet with any kind of ammo. My favorite for accuracy is PrecisionOne. And I also shoot and carry PrecisionOne Plus P. These are XTP rounds. The Pico has a strong hammer spring and Oddly enough the only failure I had, which I blame the ammo and not the gun was a Bulk Reloaded round that was know for primer strike failures. The Pico did not fire the round, but did on restrike. Which it has the ability to do. I have not tried steel case ammo and do not plan to, but I have shot a lot of variety, including quite a few defense ammunition's with no problem.I shoot a lot of bulk reloads with this gun from LAX and Freedom Munitions a lot of Fiocchi etc I have shot quite a bit of Fiocchi Extrema. Other bulk ammo as well.
I also have the Kahr, another lovely shooter. However that gun required a substantial break in and at first was finicky about ammo. Beretta changed out the springs in late 2014. Now instead of two recoil springs, just one.If you have not had your Pico upgraded, you can send it in and Beretta will do this at no charge.
I have a friend that is also a pocketgun enthusiast and shoots often. I know he will tell you the same thing as I have said. His only failure was when re-inserted the gun into the grip and it was off. I did the same thing. He is very happy his shoots the Lehigh Penatrator which I believe the early models did not like. I have not tried that round and most likely will not. .
Once again I will reiterate that I believe that the strong magazine springs need to take a "Set". Maybe I am wrong, but can only go by the results I have had with the two Pico's I own. I wish anyone that is having a issue the best of luck as these are such fine Pocket guns and such nice shooters. I am sure that if there are any issues, they can be sorted out. I know that Beretta customer service will Pick up the gun and will even deliver back to your HOUSE. (You will have to be home to sign), If you keep having a issue, I would send it in.