I like to use the EMP hold down the trigger feature. If you get it right under their feet, or right on them pretty much, it'll kill the target with one grenade. If I'm closer, I try to hit them directly without holding the trigger down. Sometimes that explosion will detonate when it hits them. The pro pipe definitely takes the most skill out of any weapon in the game. [Edited on 05.27.2011 10:44 AM PDT]