Combat Knife
The Combat Knife is an instantly lethal melee option. Unlike your normal gun bash that can’t kill in one hit from the front, the combat knife can kill in a single swing from any direction, and performs a short range lunge to score the hit.
Knife kills are also stealthy, so for a fast moving build, you can consider taking a combat knife instead of a Suppressor on your main weapon to keep its full range potential.
Using the Combat Knife well requires keen awareness and rock solid map knowledge; otherwise, you’re likely to sprint into gunfire before you can score a killing blow—and encountering two enemies at once rarely ends well.