I'm something of an optimizer, so before purchasing TTK I browsed destinydb to decide based on stats which weapons I wanted to aim for. One thing I quickly noticed was that the Omolon weapons had higher impact than their equivalent rate of fire counterparts, at some detriment. Eirene RR4 for instance appears to have higher impact than 1,000 Yard Stare with the same RoF, but has aim assist in the low 20s rather than 50s, and nearly half the inventory size. This tradeoff appealed to me, so I went out of my way to infuse and use Eirene without questioning the stats. I did the same when noticing the Omolon handcannons were similar, those being Kumakatok HC4 and the Uffern HC4. After extensively using these weapons in both PvE and PvP, it finally sunk in that their damage wasn't what it should be. Rather, there is no difference at all in damage when compared to their counterparts. I've tested this both in PvE and PvP, against other legendaries in the same RoF bracket. Of course these out-of-archetype weapons are not exclusive to TTK or Omolon. I also tested the only other I could think of pre TTK, the NL Shadow 701X, and the results were the same. Though you can clearly see the impact discrepancy from the bar values, the gun does equal damage under all circumstances. I am aware that the bar graphs on guns are extremely misleading, but the actual impact values are also listed to be higher in the DB. For your comparison convenience: http://db.destinytracker.com/compare/1703777169,3629543169,1566869545,3093674677,3883201936,3259091099 TLDR: Guns with slightly higher impact than their rate of fire archetype counterparts actually do the same damage regardless, and at the cost of lower stats which seem intended to be a tradeoff. Might be a bug, might be an oversight, but either way your Eirene/Uffern isn't as good as you may think.