This is (in my opinion) the easiest way to get the Bad Blood achievement in Resident Evil 5. Wait until Chapter Select is unlocked, load up mission 5-3 and make sure you purchase a rocket launcher. Play through the mission until the Wesker fight. Try to go through the locked metal door, and Wesker will kick you through it. Run far enough away (while beckoning Sheva to do the same) until Wesker says something about you hiding. Walk up behind him and target him with the Rocket Launcher, and he will catch the rocket. Simply shoot him anywhere with any weapon and it will explode. Achievement Unlocked. If you shoot him from the front he will dodge it instead of catching it.