Try getting the following to improve your damage:
Recondite Rings + Implosion Cards for your accesories
Ebony Greaves + Cowring/Nekoring/Pandaling/Whispering Card
Garment = +9 Heroic Backpack w/ whatever card
Armor = Brynhild/Great Old Hauberk
Upper Headgear = Drooping Amistr for PvE
Lower Headgear = Red Necktie
Additional Guns = +10 Hardened Steel Shotgun to use Spread Attack/Full Buster
Good Luck out there~