well, the idea of a nuke shotty is really nice IMHO, and both possibilities are open, either to make it as an exotic or as an unique. BFG votes for an exotic, with both types of BFG being exotic, while plasma rifle votes for unique, since the rarity of a nuke-plasma is exotic while the plasma rifle itself is common. If it shuold be made, I'd say 7d3 or 8d3 plasma spread, 21/18 ammo, 3 ammo/shot used (or ditch it, and use 6-7 and 1 per shot), plasma damage, 0.9 seconds/shot as you don't have to pump a thing. 7d3 if exotic, 8d3 if unique. Accepts common mods only as exotic, or unmoddable as unique.