AA12 / Glock Auto hip-fire only build for veteran difficulty. Tallboy / Bruiser / Crusher killer with increased weakspot damage for bosses. Trauma resistance for playing up front. Increased accuracy for tighter shotgun spread. Mobility cards for running up and engaging mutations. Inspiring Sacrifice for stacking with other teammates Inspiring Sacrifice card.
Tips: Run the AA12 with a Long-Barrel attachment to increase it's range a bit. Or put a Laser Sight on it if you want to tighten your shotgun spread even more. Use your pistol for common ridden and save your shotgun ammo for specials / bosses / hordes.