Double barrel shotgun (Doom 3)
The differences between the super shotgun and the regular one are mainly that the super shotgun (as it's nickname implies) is more effective and can cause more damage. Another significant difference is that it only holds two shells at one time (enough for one shot from the weapon) but reloads quicker than the standard shotgun. As its name implies, it uses the same kind of ammunition as the shotgun, shotgun shells.
It can only be found in Sarge’s office, since he used it for hunting and didn't carried it along with other weapons.
The best way to kill the Berserker is with the Super Shotgun: it takes less than 4 shots. And it take longer to reload but it is worth the wait considering that fact that it can blow away most enemies in a matter of only a few shots.