There are PrC with special abilities. E.g. the 5th lvl deepwood sniper´s consistent aim ( from 3.0 Masters of the wild). It allows to reroll one (two, three at levels 7/10) attack rolls with a projectile weapon per day.
I´m sure that there are some more PrC (melee/ranged) with similar abilities, but i´m without my books.
Hope, that helps.
Orm