The number of rounds fired is not as Important as how well you Know the gun.
Examples from me.
Taurus .357 mag revolver bought new.
Clean , inspect , 50 round function test. (various ammo)
Clean , inspect , 50 rounds practice. ( proposed carry ammo)
Clean , inspect , sight in with carry loads .
No problems - I'm good to go.
Sig P226 .40SW- like new CPO (Factory refurbished)
Clean , inspect , 50 round function test
Clean , inspect , Shot 3 boxes of different loads (was havin fun
)
Clean , inspect , picked carry load and shot 2 boxes / sighted in
Had no problems - but want to practice some more before I carry it.
Springer GI .45 (new)- Pretty much Same routine , but had a couple FTF/FTEs
Did a Fluff and Buff - shot some more Hard Ball
Will shoot it some more before I feel comfortable