And another highly recomended upgrade is the trigger, the stock one is garbage with the magnet. Get a nice spring trigger.
As for the barrel, if you have a place that has variable humidity, or a field that shoots **** paint, it is recommended to shoot a higher bore barrel (or freak insert system). "Smaller bore shoots most, .693 shoots all" as they say. Whether is swollen, oblong, or dimpled, .693 shoots all