The Iron Curtain SMG is a special weapon in Far Cry 6. While it cannot be upgraded at a bench, it comes with preset mods that make it very powerful. The Iron Curtain is excellent at taking apart targets at very close range but will leave you wanting from a distance.
The weapon can be found during the Balance the Books story mission. During the mission, players will end up at an enemy-occupied hotel to the west of Segunda. While there, they can jump off the pier into the water to the west of the main building, and at the bottom of the sea, they will find a chest that contains the Iron Curtain SMG.
Players can head to the area at any time but will need to be careful as it is filled with enemies. During the mission, it is possible to climb to the roof and take out all the surrounding enemies before dealing with the ones in the middle of the compound.
The Iron Curtain comes with Soft Target Rounds that do heavy damage against unarmored foes. It is also equipped with a basic suppressor. The Gunslinger mode increase the draw and holster speed, while the Keep It Cool mod will improve the suppressor cooldown rate.
The Iron Curtain is actually a superb weapon and is capable of headshot enemies from an extreme range for an SMG with one shot.