Aside from the gear choices people have posted about, the best way to pump up your Detonator damage is by having Chaos Roll & Minuet on while subbing WAR for Berserk.
It's been awhile since I've merited and I don't write down or SS my wtfpwnzorz WSes, but I distinctly remember fluctuations in my damage being mostly attributed to my buffs at the time.
And @Callisto, I'm pretty sure Skadi Bazubands will be superior to CFGs/BFGs for Detonator. The ratk is either equal or 1 fewer and you should have enough racc leftover in your head, waist, and feet slots (not to mention hopefully a sea gorget) to still land Detonator consistently enough. Don't have Skadi hands myself though, but I'll be switching to them once I get 'em.