If pitting in only light on surface and does not affect rifling geometry, ( visible only with a borescope),
Dont worry more than chech more often for cupper fouling.
Make sure the rust is all gone before shooting because rust will stick in bullet and act like an abrasive.
I have seen pittet rifle like an old 35-55 that shoot under 1.5 moa.
My old eyes just cannot do anybetter with open sight.