Apr 18, 2019
MBD (Muzzle Boresight Device) in the 120mm main gun of an M1A2SEPv2 of 1-1CAV 2nd Bde 1AD at Fort Bliss, TX (Apr 2019). Photo by SFC Sexton.
The MBD is used to periodically realign the sights of the tank with the exact alignment of the barrel. The MRS (Muzzle Reference Sensor) on top of the barrel is frequently used throughout the day to verify the alignment, as certain conditions can cause shifts in the alignment and require the gun to be boresighted again.