from my testing, %dmg currently only works with weapons that are unique or lost artifacts
for example when i have +85%dmg items and equip my snow partizen (unique wep), i can hit above the theoretical dmg values in the character stat windows (and matches with the +85%dmg), but when i have +85%dmg items and equip a regular bastard sword, i cannot hit above the theoretical dmg numbers in the character stat window
i'm pretty sure that regular weapons (aka not unique or lost artifacts) don't get the extra damage from +%dmg items, like the titan claymore (that has inherent +5% or somethin fire damage - doesn't even get +%dmg from what i remember since it isn't unique or lost artifact)
would be nice to have +dmg for all weapons