From Destinypedia, the Destiny wiki
Manufacturer:
The Drifter
Rarity class:
Legendary
Weapon type:
Grenade launcher
Min-max magazine:
6
Ammunition type:
Arc
Rate of fire:
120 RPM
Damage:
750+
Affiliation:
Gambit
Doomsday is a Legendary Grenade launcher that can be earned from Gambit Prime and The Reckoning.