We're All Very Impressed, Trust Me Achievement Guide

This is not a story related achievement, but it is not missable as it can be done at any time throughout the game. It is likely to be attained quite early on, especially if you use Kenny frequently. In order to attain this achievement, use Kenny's glob shot (RB / R1 attack) towards any enemy G3. Any run of the mill grunt will do. Then shoot the enemy five times while they are in the air. The achievement will pop immediately. The G3 scum will most likely die before they hit the ground.