General-purpose viral+rad build, good up to level 120 or so. Use the primary semi-auto mode by default, switching to full-auto only as needed to pop nullifiers or snipe things at range. The primary fire is of course silenced by default, so this works particularly well on [Ivara], who finally has a contender for her primary slot that isn't the [Baza] or the [Lenz].
Putting [Wildfire] in the last slot converts the base electric damage to radiation, making it stronger against armored targets, and also gives you a 7th shot before being forced to reload. The battery-charged ammo on the [Fulmin] means that sometimes you only have enough time to partially recharge, so having a larger magazine will let you fight for longer without having to stop and fully reload. However, it is certainly the weakest mod in the set, and may be replaced depending on the mission.
For missions where you reliably have enough downtime between fights to fully reload, replace [Wildfire] with Vigilante Armaments for better burst damage, especially against unarmored targets.
For missions with especially high-level enemies where you can't rely on full armor/shield stripping from the rest of your squad, replace [Wildfire] with [Hunter Munitions] to get some damage that bypasses armor and shields. The high crit chance and viral damage typing from the rest of the mods means that [Hunter Munitions] is about as effective as it ever is, although do note that it is less raw damage per shot than [Wildfire] or Armaments against enemies with more normal amounts of eHP.
Adding a 7th forma (V polarity) also allows the use of Primed Bane of (Faction), which is stronger than [Vigilante Armaments] when fighting the particular faction chosen.
Do not use [Shred] or its Primed variant for this build; you will spend most of your time reloading. They are better used in builds that focus on corrosive damage for the full-auto firing mode, which is much more ammo efficient.