This is a weapon mission that requires the player to finish a match in 1st position using the grenade launcher. If you use any other weapon during the match then you can't complete the mission in that match. Only the Grenade Launcher is allowed to be used.
"Finish a match in 1st position using only the Grenade Launcher."
Collect medals whenever you get the chance. Select small maps and if you are not very good with the grenade launcher, go here.
- Interestingly enough, you can complete this mission by using the Flare Gun MK2.