Which individual is responsible for manipulating the sight and laying the mortar for deflection?

The gunner is the individual responsible for manipulating the sight and laying the mortar for deflection because their primary role involves directing the mortar's aim based on the target's location and desired impact. This requires a deep understanding of how various factors such as range, wind, and projectile characteristics affect the trajectory of the mortar round.

The gunner must engage with the sighting mechanisms to ensure precision in targeting and adjusting for any external influences that may alter the projectile's path. This task is critical for maintaining accuracy and effectiveness in mortar operations. The gunner's knowledge and skills ensure that the mortar can hit designated targets reliably, which is essential for the success of any fire mission.

Other roles, such as the assistant gunner or spotter, support the gunner but do not have the primary responsibility for manipulating the sight. The ammunition bearer’s main duty is to transport and supply ammunition rather than to adjust the sight for aiming. Therefore, the gunner's expertise and direct involvement in aiming and deflection lay the foundation for effective mortar fire.