The Ultimate Fulmin Prime Build in Warframe for Steel Path & Deep Archimedea

If you can’t decide between a shotgun and an assault rifle, worry not because the Fulmin lets you have the best of both worlds. While you’re at it, you might as well get the Fulmin Prime, which is the more powerful and flexible upgrade for this beloved primary weapon in Warframe. As with all things Prime, you’ll want to build them right. So here’s our Fulmin Prime build for Warframe— you can take it to Steel Path and even Deep Archimedea content.

[Updated on September 20, 2024 – Guide revised with a table and more details]

Build Mods, Arcanes, & Forma

We know that constantly changing your mods to combat specific factions is annoying, so we’re not going to force some Faction-specific mods with this particular build (though that’s still an option). However, the tradeoff is that you need around seven Forma for this build.

That’s because there are three Galvanized mods and some maxed-out Rank 10 mods that will eat up the drain capacity. You can opt to use under-leveled mods, of course, to save on Forma, but expect lower DPS.

Without further ado, here’s the build:

Mod	Effect	Alternative(s)
Terminal Velocity	+60% Projectile Speed	Sinister Reach for additional range.
Galvanized Chamber	+80% Multishot | On Kill: +30% Multishot for 20s. Stacks up to 5x.	Split Chamber, but it will be weaker.
Galvanized Scope	On Headshot: +120% Critical Chance when Aiming for 12s | On Headshot Kill: +40% Critical Chance when Aiming for 12s. Stacks up to 5x.	Argon Scope is a more relaxed alternative.
Galvanized Aptitude	+80% Status Chance | On Kill: +40% Direct Damage per Status Type affecting the target for 20s. Stacks up to 2x.	Rifle Aptitude. But again, it will be weaker.
Vital Sense	+120% Critical Damage	None
Critical Delay	+200% Critical Chance -20% Fire Rate (x2 for Bows)	None
Heavy Caliber	+165% Damage -55% Accuracy	None
Internal Bleeding	Impact Status Effects have 35% chance to apply a Slash Status Effect (x2 when Fire Rate is below 2.5)	None, you need this for high-level enemies.
Serration	+165% Damage	Use Bane mods or Primed Bane mods if you don’t mind switching mods between missions You can also use Bladed Rounds.

You’ll be relying on the Impact and Internal Bleeding combo to get this build going and dealing some absurd damage–even to armored enemies. However, if the enemy level gets too high (past Level 150 or so) then you will have to rely on priming or stacking status effects on your enemies, with Viral on top of the priority status effects.

For that matter, you also want a Kuva Nukor or Tener Cycron to spread these status effects and trigger Galvanized Aptitude’s bonus.

Arcanes for the Fulmin Prime Build

Your Arcane option is really limited here and there are only a few good choices, and the first one would be Primary Merciless. This Arcane will allow you to reload much faster though the damage stack might not look ideal.

Still, with how Fulmin Prime works, you need as much reload speed as you can especially if you’re in shotgun mode so you can keep firing shortly after exhausting your limited shotgun ammunition. This helps a lot in maintaining your DPS.

Primary Deadhead is a more straightforward damage boost especially if you find yourself being conservative with your ammunition. It offers a higher DPS boost for this Fulmin Prime build especially if you’re already using Galvanized Scope.

Fulmin Prime Playstyle

For content below Level 150 or typically Steel Path dregs and cannon fodder, you can just empty your mags on them. They won’t put up much resistance. However, if you find some tough Eximus units or if you’re in Deep Archimedea or Netracells, try out the following steps.

1. Bring out your primer (Kuva Nukor / Tenet Cycron / Epitaph).
2. Apply as many status effects as you can on your target or target cluster.
3. Ensure your targets are afflicted with Viral at the very least.
4. Switch to Fulmin, you want Impact to proc so use shotgun or Semi-Auto mode.
5. Maintain your aiming mode and go for headshots.
6. Use Semi-Auto or shotgun mode for enemies hiding behind cover and for stealth missions.
7. Use the rifle or Full-Auto mode for faraway enemies.

For better fire mode swapping speed, you can use Wisp or Wisp Prime as she halves down the swapping speed from one second to 0.5 seconds. With the right rotation and good aim, no enemy will stand more than a few seconds against this Fulmin Prime build in Warframe.