WHY MAGNETIC PROGENITOR
Magnetic Progenitor is the most flexible innate element, since it allows you to form specific elemental combinations easier. For example, choosing heat means you cannot make Pure toxin on alt-fire nor pure corrosive without adding a heat mod. Choosing toxin means you cannot make Pure Radiation on primary without adding three elemental mods and also potentially makes gas due to the innate heat. Magnetic status also gives an extra free element for Galvanized shot on the primary fire, as well as increases damage to shields as a status effect.

MOD BREAKDOWN

• Galvanized Shot: Galvanized Shot is mainly for primary fire or primary/alt fire hybrid with a focus on alt-fire DIREC HITS (Note: Galv Shot is Multiplicative to Cascadia Flare on alt-fire DIRECT HITS and doesn't work at all on the AOE component). If you want to focus PURELY on AOE Alt-fire, swap Galvanized Shot for either Primed Fulmination, Primed Expel, Hornet Strike

• Galvanized Diffusion: Mandatory multishot

• Primed Pistol Gambit and Primed Target Cracker: mandatory crit mods

• [Ice Storm] and [Pistol Pestilence]: [Ice Storm] increases magazine capacity which directly multiplies alt fire damage by 1.4x. [Pistol Pestilence] helps make viral damage which has a 1.75x bonus against cloned flesh and viral status which increases all damage to health by up to 4.25x at 10 viral stacks.

• [Primed Heated Charge]: gives an 82% increase in raw damage with a 1.25x bonus against cloned flesh. Any heat status will continue to deal damage over time.

• [Lethal Torrent]: gives more multishot and firerate

Flexible options
(Both Galv Shot and Lethal Torrent are flexible options):
Primed Expel - 1.55x multiplier against a specific faction, for +55% DPS boost on raw damage and +141% DPS boost on heat procs
Hornet Strike - additive to Cascadia Flare, giving +38% DPS boost
Primed Slip Magazine - additive to Ice Storm, giving +39% DPS boost to ALT-FIRE only
Anemic Agility - helps further improve fire rate and charge rate

ELEMENTAL COMBINATIONS:

Viral Heat: This is the 'standard' combination which has highest effectiveness against most grineer and corrupted enemies, particularly with armor strip.

Corrosive Heat : [Ice Storm] is flexible for [Primed Convulsion] to make Corrosive Heat, good against Deimos infested as well as Acolytes and specific Grineer enemies that possess Ferrite armor

Radiation (archons/angels/murmur): Swap [Ice Storm] and [Pistol Pestilence] out for [Primed Convulsion] and either [Anemic Agility] or [Hornet Strike].

Viral Electric (stripped murmur and corpus machines): Swap [Primed Heated Charge] for [Primed Convulsion] to make Viral electric. Electric has a strong bonus against murmur enemies and corpus machines (such as Lua demolysts).