Which type of ammunition is specifically used for marksmanship training with the M240?

M80 Ball ammunition is specifically designed for marksmanship training with the M240. This type of cartridge is a standard military round that combines both accuracy and effective ballistics, making it suitable for training exercises. It provides the necessary performance characteristics to closely mimic the conditions of live fire in a controlled training environment, allowing soldiers to gain proficiency in using the weapon without the potential variables introduced by other types of ammunition.

While other types of rounds have their specific uses, M80 Ball rounds are preferred for general marksmanship purposes due to their reliability, consistency, and the ability to simulate actual combat conditions effectively. Tracer rounds, for example, are used to provide a visible flight path but can be less practical for training purposes since they can distract from marksmanship fundamentals. Dummy rounds, on the other hand, serve a different purpose such as practice without live ammunition and do not replicate the recoil and report of firing a live round, making them less useful for actual marksmanship training. Armor-piercing rounds are designed for penetrating armor and are not typically used in standard training scenarios.