Check my profile for other builds made by me.
Credential's: 450+ hours in Nightmare running various builds.
The team's roles should be:
1) Frontline: Main purpose is to apply shredder through Shotgun/SMG OR play Melee and be a drain tank
2) Second in Line: Assault rifle user who focuses on precision kills to melt common hoards or apply shredder if Melee is present
3) Primary DPS: Sniper, their entire role is to focus only mutations and mark them with marked for death to shout out to the team who he is focusing.
4) Anchor: The one watching the back, usually a medic/support who ensures the Primary DPS survives.
The main downfall of playing Assault rifles is the long reload times. So to offset this you're required to grab:
Widemouth Magwell +30% reload speed
Cold Brew Coffee +15% reload speed
Reload Drills +20% reload speed
Avenge the Fallen: stacking +20% reload speed conditional on team incap
In The Zone: Stacking +5% reload speed up to 50% reload speed conditional on precision kills
Tactical Vest is an obvious choice +30% Ammo Capacity to your desired weapon choice +10% damage with Assault Rifles.
Broadside is used to focus commons as that's your entire purpose in life is to mow down 90% of this game's enemies. Keep in mind if you funnel them a single bullet can kill 3-5 ridden. But in general the gimmick of this entire build is precision which falls down on your FPS skills. This can be interchanged with Shredder if you have a Melee as your frontliner instead of a Shotgun/SMG. Unfortunately your team will have to deal with you having it a bit late as you need Widemouth Magwell, Tactical Vest, and Cold Brew Coffee first. If you already have a Shredder on your team though keep it in your deck for super late game, but skip over it for other cards.
Avenge The Fallen is just a damage amp that infinitely stacks providing your sniper the capability one tapping bruisers and you the ability to melt mutations as well. The infinite ammo rarely matters but in niche cases may keep your team alive.
Run Like Hell + Mad Dash combo: Even with Marathon Runner being added into the game (with the removal of sprint disable it's now viable) you're going to want to ignore it's existence. This is due to the fact you'll be in direct contact with mutations like Tall Boys, Exploders, and Reekers. With being second in line you'll be so close to the action you're in immediate threat range of excessive damage from tallboys sprinting or exploders catching you in a corner, or Reeker guts causing another hoard. So relocation power is more important that backpedaling kiting potential.
Late game when mutations get prefixes like Monsterous you'll want weakspot damage so your damage doesn't fall off:
Hyper-Focused +50% Weakspot damage
Reckless Strategy +30% weakspot damage
Knowledge is power +10% weakspot damage (plus being able to call out how healthy something is for your team)
Ridden Slayer +20% weakspot damage
Ammo For All is effectively +40% ammo for your team not only giving you +40% Rifle ammunition but giving your team deeper pockets to accept their needed ammo type preventing awkward out of ammo situations across the team.