The HC type for TDYD is a higher fire rate, lower impact than let's say based off of TDYK. So of course it isn't going to outperform a FB because that weapon is based off the latter, TDYK. Now, if you had a TDYK, Red Hand XIII you would notice that the base damage does do more than FB. And HC's in a different category, like Timur's Lash. But that still doesn't account for firefly, being that it allows you to do more dps in a crowd of enemies than any hand cannon currently. And honestly, you will only see the need to change the weapon when fighting lv36 HoW enemies, if that.