Rupture a total of 200 enemies using the Rocket Launcher.

Once you have the Rocket Launcher, simply use it to kill enemies. You can easily boost this achievement by playing the Mutant Bash TV game mode, as much as you wish. You will unlock Mutant Bash TV during the main story mission 'Wasteland Celebrity' and can return at any time, as many times as you wish. Before starting a round you can choose a specific challenge, 1 of which is Grenades and Rocket Launchers only and you will have an unlimited amount of ammo. You can get dozens of kills per run of Mutant Bash TV and can repeat it as much as you need to get 200 kills. You can also do this without ever finding the Rocket Launcher for personal use if you so choose.