When you're running low on EVE, the Grenade Launcher is your most effective defense against an angry Big Daddy. Once you have the damage immunity upgrade, there's really no reason not to use up any and all ammunition you find for this weapon. The potent explosions it triggers will put any opponent on its back in no time.
Your first opportunity to pick up this weapon is from Peach Wilkins' conveyor belt in Neptune's Bounty.
Ammunition
Frag Grenade
These basic frag grenades are massively damaging, and have a significant blast radius. Beware of flying body parts.
This ammunition has a carry capacity of 12 and a load capacity of 6.
Proximity Mine
These are effectively used as landmines, staying primed and ready until an unwitting victim walks too close. They can also be used as a standard frag grenade if you score a direct hit.
This ammunition has a carry capacity of 6 and a load capacity of 6.
Heat-Seeking RPG
These homing missiles are the perfect solution for moving targets, delivering a devastating payload even around corners! Adult supervision recommended.
This ammunition has a carry capacity of 6 and a load capacity of 6.
Upgrades
Grenade Launcher Damage Increase
Incendiary injectors increase the damage of the Grenade Launcher. All of the above ammunition really packs a punch once you have this upgrade.
Grenade Launcher Damage Immunity
Autogenerated shape charges make you immune to the damage from your own grenades. An excellent upgrade, especially if you spend most of your encounters with Rapture's denizens up close and personal.