An easy strategy to succeed with the grenade Launcher is to shoot near the enemies instead of at them. When the grenades explode, they will all explode at once, dealing a large burst of damage before the enemies even begin approaching you.
Grenade Launchers are also extremely well suited for taking out groups of enemies, as explosions seem to have no limit as to the amount of enemies that can be injured in a single blast. Grenade Launcher grenades also bounce off walls and ceilings, allowing you to hit enemies that might not be in direct line of sight.
Grenades do have a downside, however - they can damage allies even when PvP is off. The player wielding the grenade needs to take care when firing a grenade launcher near allies, as a hit from a grenade can devastate many players.
Like most other ranged weaponry, Grenade Launchers cannot be crafted. Below are methods to obtain them: