The Venom shotgun was developed by the salarianSpecial Tasks Group to meet the unpredictable needs of those stationed in hostile areas. The double barrel fires ammunition that detonates on impact, while a third barrel below can be charged to fire a round of microgrenades. Given the nature of most STG assignments, the Venom was designed to force an exit strategy and was issued to teams whose primary objective was to extract compromised undercover operatives. The shotgun is now issued to frontline soldiers in the war against the Reapers.
Treat the Venom like a grenade launcher. This weapon's main asset is its high damage. It has 2 firing modes:
Uncharged - fire one explosive round on a shallow trajectory to target that detonates on impact.
Charged - fire one round on a shallow trajectory to target that separates into five bomblets on impact, which in turn detonate. The overall damage is greater. Note that AI squadmates will only fire uncharged shots when armed with this weapon.
The Venom's main disadvantage is its weight, and players reliant on tech and/or biotic powers should take note of this. Even after upgrading the Venom to rank X, it remains considerably heavier than other shotguns such as the M-11 Wraith. You may not need to have other weapons in the loadout, and it can be better to enjoy the bonus to power recharge speed.
Charged shots can be used to bombard groups of targets at range, or attempt trick shots exploiting walls and ceilings to rain bomblets against enemies that took cover. You can also flush targets out of cover by firing it to the side of where they're hiding, and letting the spread do the work. Because it is explosive-based, mods that enhance penetration serve no purpose.
Explosive shots can blow enemy bodies into scraps to prevent Cannibals from consuming them and restoring their armour.
The Venom can deal considerable damage even on Insanity difficulty with the proper loadout. It has one of the fastest times to kill any unit: At rank X, with the Shotgun Extended Barrel mod equipped and Incendiary Ammo active, a single charged shot from the Venom that hits its mark can instantly kill tough enemies like Brutes and Phantoms, and three to four charged shots can easily take down Atlases, Geth Primes, Adjutants, Harvesters and Banshees. This factor is not to be underestimated. It functions quite literally as the Heavy Weapons did from Mass Effect 2, if used with the same sorts of moderation.
It can be wise to pair this with the soldier, as a result of its weight and the class's reduced dependence on active powers, and specialize with damage mods and armor pieces to further boost the Venom's performance.
Because the Venom uses an explosive charge as its method of attack, it is not capable of penetrating armor, even with an armor penetrating mod, such as the Shredder, High Velocity Barrel, or Armor-Piercing ammo.