For this achievement you need to fire off 50 grenades from the 'Grenade Launcher' and then go onto win the match.
The easiest way obviously is with a second controller in a local match with the following settings:
• Map - Any
• Gamemode - Hillcampers
• Gamemode settings:
- Score to win 5
- Weapon selection Grenade Launcher
• All other settings default.
Once the match loads up aim for a spot that wont rebound the grenade back at you and start pressing
over and over to fire a total of 50+ grenades off, once you've done at least 50 walk to wherever the hill is and sit in it to win the match.You can fire more than 50 as that's fine