The basic idea is simple: get an AA12 shotgun (preferably with extended mag and stumble dmg) and get into their face!
Benefits:
+ high dps
+ high survivability (trauma resist and temp hp keep you alive and topped up at all times)
+ great horde clearing
+ great specials and boss kill potential (40% weak spot dmg = A LOT of dmg)
Drawbacks:
- average move speed
- might get low on ammo sometimes