Vigilant supplies to get more ammo more easily and for the passive 5% chance of increasing crit tier.
[Primed Ravage] and [Critical Deceleration] to get crit chance and balance the build.
Galvanized mods and Primary Merciless to get more damage on kill since we do a decent amount of damage (i cannot find a way to use [Blaze] mod tho so we lost a bit of burst but it allow us to place [Primed Tactical Pump] for more sustain damage as the reload now take less than a sec)
To finish Primed Chilling Grasp and Toxic Barrage for viral and extra status chance/projectiles. And [Incendiary Coat] to get fire (Primed Shocked Shell might be better to get burst damage as we get an extra 100k damage, but the sustain only gain 50k so it need to be tested, also i'm not sure electricity would be better)

This build is actually pure theory and hasnt been tested yet. He is here to get comments and be upgraded after test has been run on it.
Thx for the help in comments and hope this build isn't that bad ^^.