Had an idea and it panned out really well.
Musket blunderbuss using sticky, powder, ss, and splitting nade, mortar, and shrapnel blast. All ignited gems and fire dmg ring. Ignited ruby in musket and a t2 ruby in BB (think this is more dmg at 300 int than ignited diamond).
Im having a lot of fun with this build. Only BB perk i have is plagued splitting nade keen vic on thd bb. Maybe would like resupplying mortar charge on gear. I feel like the plagued nades really help the mortar charges deliver aoe clump punishment, and a sticky bomb beforehand can decimate.
Biggest problem is this build is trash 1v1