From Quake Wiki
The Double-Barrelled Shotgun uses 2 shells up per shot, but is a lot more effective at close range than the Shotgun. It is probably the most-used weapon in the game, and you'll first find it in a secret in E1M1, or else in E1M2.
The term "Super Shotgun" might sometimes be used to describe this gun in fewer syllables, but this is technically incorrect. Both Doom 2 and Quake II used this term, but in Quake it is called the Double-Barrelled Shotgun. Still, its spawn function refers to it as weapon_supershotgun.
|Weapons from Quake|
|Axe | Shotgun | Double-Barrelled Shotgun | Nailgun | Super Nailgun | Grenade Launcher | Rocket Launcher | Thunderbolt|