Personally, 200-250. That's draw and fire practice, not just static hole punching, with several mag-dumps back to back, and no real cleaning or service beyond a cursory glance and a quick wipe-down in between range trips.
I have no doubts about my shooting. My question was when you feel you can rely upon a new weapon. For me its around 500 trouble free rounds, through several magazines, and including at least 50 carry rounds.No matter what the weapon, keep practicing. There is not a magical number, just how well you shoot.