Berserk

The Berserk is a power-up that temporarily increases the fire rate and/or damage of the player's weapons.

Unreal Tournament 2003/2004
In UT2003 and UT2004 Berserk is an Adrenaline combo that lasts for about 27 seconds. It increases the player's damage output by about 33% by either increasing the firing rate or (e.g. for rapid fire weapons like the minigun) damage accordingly. The game also features a Super Berserk mutator, which permanently increases the firing rate or damage for all players, and the increase is much stronger that the Berserk combo.

Unreal Tournament 3
For most weapons the Berserk simply doubles the firing rate or charge-up speed. Some firing modes that already have a very fast rate of doing damage simply apply double damage, similarly to the Damage Amp.

Picking up the Berserk while already carrying Damage Amp or Invulnerability or picking up any of those power-ups while already carrying the Berserk gives the user a "Juggernaut" award.