Tried a couple of things on this thing and this seems to work quite well.

It's a bit on the Forma heavy side due to the use of 3 R10 mods but oh well...
[Hammer Shot] is kind of the interchangeable mod here, I tried [Vigilante Armaments] but it seems like HS is the better option.
Add another Forma and you could slot maybe [Galvanized Scope] for that extra crit or probably the best alternative would be [Primed Bane Of Grineer] and its respective others.
[Tactical Reload] can be interchanged as well for whatever you prefer, I kinda like the passive reload while melee.

The only MEHH I currently have with this is that you can't equip [Terminal Velocity] as the bullets can be quite slow at times, especially at "long" ranges.

As of now, I feel like this is an underrated gun, that hopefully sees a bit of a Riven disposition buff in the future apparently the Ingame dispo is bugged as of now; 1.25 dispo is more than enough to make this shine.
A good roll would be +cd (preferably more than [Vital Sense] to replace it or [Hammer Shot]), +cc (to replace [Critical Delay], without the fire rate penalty) or something like +120 sc +cold +toxin, that would probably be a god roll for this