What type of ammunition is primarily used for marksmanship training?

The M80 Ball ammunition is primarily used for marksmanship training due to its design and performance characteristics. The M80 Ball is a full metal jacket round that is suitable for a wide range of shooting activities, including target practice and qualifications. Its standard projectile weight and ballistics provide a predictable performance, making it an ideal choice for developing shooting skills and ensuring accuracy in various shooting conditions.

In contrast, other options such as the M41 Ball serve different purposes, such as specific training scenarios or units, and M855 Tracer ammunition is designed for visual tracking of the round's trajectory during training rather than general marksmanship practice. The MK 3A2 is typically used for specialized applications rather than marksmanship training. The suitability of the M80 Ball for a variety of training environments and its reliability as a standard service round solidifies its role as the primary choice for marksmanship training.