Muzzle reference system

The mirror for the muzzle reference system on this Royal Ordnance L11 is inside the metal housing on top of the barrel.

A muzzle reference system is a device used on most modern tank guns and some artillery systems that measures the bending of the barrel due to heat, gravity and other issues. It normally consists of a laser device and detector mounted at the breach end of the gun, often co-located with other optics like the gunner's sight, and a mirror at the muzzle. By measuring the deflection of the barrel, corrections can be applied by the ballistic computer to correct for changes as the gun is fired.

References

• Dursun, Tolga; Buyukcivelek, Firat; Utlu, Çağrıhan (May 2017). "A review on the gun barrel vibrations and control for a main battle tank". Defence Technology. doi:10.1016/j.dt.2017.05.010.