My understanding of Eve mechanics is sometimes spotty. I know there are knowledgeable people on these forums, though.
I have tried using fury light missiles on the SOE epic arc and they seemed to apply less damage than the regular light missiles, even to cruiser sizes opponents. Today, I tried fury cruise missiles against the final boss in the Amarr Epic Arc - Harkans Behemoth. The fury cruise missiles applied noticeably less damage than the regular cruise missiles. These Tech II missiles have a shorter range and more of a dependence on signature radius than the Tech I missiles - is the signature radius penalty so significant that it cannot apply full damage even to battleships?
I suppose I could check this in Pyfa, but I wouldn’t know where to get the stats for the NPC.