Improved Piercing Shot
Your sling attacks can ignore damage reduction.
Prerequisite: Piercing Shot, base attack bonus +6.
Benefits: When making a sling attack against a target within its first range increment, you ignore an amount of damage reduction equal to 1/2 your base attack bonus.
*This feat benefits users of the sling or halfling staff-sling, and is the original concept of Weirdo and Xunal on the Homebrew thread of the Paizo RPG website. (Weirdo; Improved Penetrating Sling feat).