Grenade Launcher

From: Special
Chapter: 3 · Yard & Old House

Damage: ~800 impact (±50%) + burn: ~2000 Flame / ~2400 Neuro in total
Magazine: 1
Slots: 2
Ammo: Flame Rounds / Neuro Rounds (5 per slot)
Total on Normal: 9 Flame Rounds + 4 Neuro Rounds

How to get it

Easy and Normal: Main House 1F, Supplies (the crow door in the Drawing Room; needs the Crow Key from the Old House), on the white tarpaulin opposite the door. Madhouse: in Zoe's trailer (Yard), on the bench opposite the door. If you never pick it up, it turns up in the Swamp Mine Office (ch07).

Verdict

Pick it up (it is free) and spend the rounds on Fat Molded and Crawler groups, not on Marguerite.

Craft rounds: Strong Chem Fluid + Solid Fuel = 2 Flame Rounds; Strong Chem Fluid + Supplements = 2 Neuro Rounds.
2 Flame Rounds knock a Fat Molded down. Neuro Rounds slow Molded and hurt them badly.
Barn Fat Molded (ch04): Neuro to stun it, then Enhanced headshots.
Any grenade kills Crawler Molded inside the blast.
At point blank it hurts you too.

Against Marguerite in the Greenhouse it loses 60% to 90% of its damage, and 50% to 75% against Mutated Jack, even though several guides call it a boss killer. The burn can still pop Jack eyes you have no line of sight to.

In the last phase against Eveline, fire this and the 44 MAG first.

Nightmare: 50 Scrap. Ethan Must Die: silver chest (4 stars).