"The grenades from this launcher explode on contact with enemies, and its expanded clip and radius give it more flexibility than the Arx Buster." In-game Description.
The Grenade Launcher fires time-delayed grenades that will bounce off surfaces unless they impact a player or base asset. These grenades fire in an arc similar to the Fusion Mortar used by the Juggernaut, although not as far. The launcher has a fairly fast firing rate allowing the Raider to fill a room with explosives before the enemy knows where they are coming from.
The Grenade Launcher is very effective indoors because it can bounce around corners. For this reason it is often used to attack the generator and clear out deployable defenses. It is also effective when flying above an enemy player because the radius almost ensures you will hit them. Fire off three or four shots in a row and carpet bomb the area below you. In maps with big flag stands like Drydock the Grenade Launcher combined with the Shield or Jammer Pack and Cluster or EMP Grenades can clear the flag stand very quickly.