Xernuht
[10] Knight
You don't really want to quickshot+melee in mercs unless it's a weapon zombie and even then it's better to counter for the time. Against weaponless zombies in UC you should headshot+melee because it kills faster and uses less stamina. In mining the depths you should counter all gunless zombies.
Magnum is great in Mercs for taking down bosses or for saving a combo with a fast kill.
Well I never said I was good at it...