What is the sustained rate of fire of the M120?

The sustained rate of fire for the M120 mortar is defined as the ability to maintain consistent firing over an extended period while preventing overheating and excessive wear on the weapon system. The correct answer, identifying a sustained rate of 4 rounds per minute indefinitely, reflects the mortar's design and operational capabilities to effectively engage targets without compromising the integrity of the weapon.

This value allows for a balance between firepower and artillery sustainability, enabling operators to deliver accurate and timely fire support in various combat scenarios. Maintaining this rate ensures that the crew can continuously engage targets while adhering to necessary cooling periods, thus maximizing the efficiency of the mortar system for prolonged operations. Other rates of fire are either too high for sustained engagement or pertain more to immediate firing capabilities rather than the sustained aspect, which is critical in prolonged engagements.