What rate of fire is considered sustained for the M240?

The sustained rate of fire for the M240 is defined as 100 rounds per minute (RPM). This rate is designed to allow the gunner to maintain effective fire over longer periods while preventing overheating of the weapon. Sustained fire is critical during extended engagements where a high volume of rounds could lead to equipment failure or unsafe operating conditions.

In contrast, higher rates of fire, such as those indicated in the other choices, represent different firing categories such as rapid or cyclic rates, which are not sustainable over long durations. These rates are more suited for situations requiring immediate, high volume suppressive fire but come with the risk of overheating the barrel and other components. Understanding the different rates of fire helps operators use the M240 effectively, ensuring operational readiness while minimizing wear and tear on the weapon.