200 Rounds
-
At least...
https://www.shootingillustrated.com/content/do-pistols-need-a-break-in-period/
Now, there are some exceptions...I'd expect something from Wilson Combat to shoot nickels at 25 feet and go bang every time, but that's a custom made, hand-fitted pistol. If you've never shot a pistol like that, it's like comparing good spinet to a good seven-foot grand.
But for us everyday folks buying off the shelf, shooting one in helps. A lot.