Just to be safe I prefer to run 500 rounds through a new gun or a gun that has had work done/parts replaced to "prove" it. I more or less pulled this number out of thin air without very much research but it seems to meet or exceed everything I've come across from professional recommendation to manufacturers suggested break-in. After that 100 or if I can swing it 200 rounds of carry ammo in the mags I'll be using. Obviously more is better. The larger your sample size the more accurate the results so 100% reliability through 500 rounds is going to mean more than 100% through 100 rounds.
I don't collect guns, I accumulate them.