A wellbore tool string includes a perforating gun having a plurality of explosive perforating charges and a shock mitigation tool. The shock mitigation tool including a tubular body having a top end, a bottom end, and a chamber; a barrier disposed proximate the bottom end in communication with the chamber; and a plurality of actuators connected with the body proximate to the top end of the body, each actuator opening a port in the body providing fluid communication with the chamber when the plurality of actuators are activated.