FMJ works in Warzone, but there's a common misconception about the perk that might bring about confusion. The perk has been in Call of Duty games ever since the beginning and new players miss a detail about it that changes the perk entirely. FMJ, or Full Metal Jacket, increases bullet penetration and damage against equipment and killstreaks.

It does not increase damage to enemy players.

No point running FMJ in Warzone imo. Doesn’t add damage to the gun, just gives you better penetration through walls. I’d rather have an extra attachment instead ?

— JackFrags (@jackfrags) May 7, 2020

How does FMJ Work in Warzone?

FMJ works the exact same way in Warzone as it would in the multiplayer mode of Modern Warfare. Although on the loadout screen, the FMJ perk will increase the damage stat to your weapon, it will not increase damage to players, but only killstreaks and equipment. So, helicopters, jeeps, trophy systems, etc. will all take more damage from a weapon with the FMJ perk, but other enemies will not.

Armor does not count as equipment here, so the FMJ perk does not increase penetration on armor. It will still take the same amount of shots to down and enemy whether or not you have the FMJ perk enabled.

The FMJ perk will increase your damage through cover, so if someone is behind a wall or hiding behind a different structure, the FMJ perk will help in this case, but not in an open battlefield with no objects in the way.

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