The Harbinger is a Weapon Blueprint available in Call of Duty: Modern Warfare 3 (2022) and Call of Duty: Warzone 2.
It is a blueprint variant of the base weapon FTac Recon, one of the Battle Rifles featured in Call of Duty Modern Warfare 3.
You can find all the attachments for the Modern Warfare 3 and Warzone 2 Harbinger Blueprint listed below.
Here are the attachments for the Harbinger Blueprint featured in Call of Duty: Modern Warfare 3 and Call of Duty: Warzone 2.
You can build your own Harbinger weapon Blueprint by adding these attachments on a base in the Gunsmith menu.
To unlock the Harbinger Blueprint in Warzone 2 and Modern Warfare 3 you need to complete the DMZ Mission "Nail In The Coffin".