What is the sustained rate of fire for the M4 carbine?

The sustained rate of fire for the M4 carbine is indeed 12-15 rounds per minute. This rate reflects a balance between maintaining accuracy and preventing overheating of the weapon. Sustained fire is characterized by a steady rate that allows the operator to engage a target effectively over time without excessive barrel heat, which can compromise accuracy and reliability.

In practical terms, the sustained rate is designed for situations where the shooter must fire consistently over longer periods, such as during troop movements or while providing overwatch. This approach helps in managing fatigue and maintaining control during engagements.

The other choices, while reflecting various rates of fire, do not represent the sustained firing capability of the M4. Higher rates, like those in the 400-600 rpm range, indicate a cyclic rate or rapid firing suitable for short bursts rather than sustained engagements, which can lead to overheating and reduce accuracy. The lower rates, notably those beyond the sustained rate, do not align with the operational effectiveness expected from the M4 carbine in a sustained fire scenario.