Various detachable firearm mounting bracket device embodiments are provided. According to an embodiment, a detachable mounting bracket is adapted to allow users of various weapons platforms and field optical devices to rapidly and securely attach visual augmentation devices to a firearm. A detachable mounting bracket can comprise a housing to attach to a firearm stock, a clamping mechanism to secure the housing to a firearm, and a rail interface adapted to receive a visual augmentation device. The detachable mounting bracket device can be attached to a firearm with a clamp, screw closure, and a vertical interlock clamp. After the detachable mounting bracket is attached to a firearm, a user can easily and rapidly secure a visual augmentation device to the rail interface. Other embodiments are also claimed and described.