History of Killing Tally

Killing Tally is a weapon trait: kills increase the weapon's damage until it is stowed or reloaded. It grants up to 3 stacks: 10%, 20% and 30% damage at 1, 2 and 3 stacks. A PvP value of 5/10/15% is also reported.

Notes

It was introduced in Season 17, though one wiki gives Season 6. It is commonly found on Trace Rifles and Machine Guns. It appears on Ulterior Observation.