This build works with either a Ranch Rifle(swap stock pouch to tac vest) or preferably the Phoenix or a Barrett. The only flex card here is Overwatch. I like overwatch as 5 temp health per kill is a huge boost to your front liners health. Your job is to kill mutations fast, so movement speed to reposition yourself for enemy weak spots is key. Swap the flex mentioned above for Confident Killer if you feel like you need more damage.