Rampage

Rampage is a Trait perk: each kill with the weapon temporarily increases its damage, stacking up to three times. PvE values are about +10%, +21% and +33% at one, two and three stacks. PvP values are +10%, +20% and +30%. Stacks last 3.5 seconds (4.5 seconds in some versions), and each kill refreshes the timer.

Applicable weapon types include Auto Rifles, Hand Cannons, Pulse Rifles, Scout Rifles, Sidearms, Fusion Rifles, Grenade Launchers and Shotguns. It appears on many weapons, including the Void machine gun Hammerhead.