What is a key feature of the M16A2 service rifle?

The M16A2 service rifle's designation as a shoulder-fired weapon is a key feature that significantly contributes to its effectiveness in combat situations. This design allows for better stability and accuracy when firing, as the weapon is braced against the shoulder of the user, which enables more controlled and repeatable shots. The ergonomics of the M16A2, along with its lightweight construction, make it maneuverable, allowing Marines to engage effectively in a variety of combat scenarios.

Additionally, the M16A2 is designed for semi-automatic and three-round burst modes rather than continuous automatic fire, which allows the user to conserve ammunition while maintaining accuracy. Its gas-operated, rotating bolt mechanism is also vital for its operation, differing from a bolt-action mechanism, which would require manual cycling after each shot. Thus, emphasizing that the M16A2 is primarily a shoulder-fired weapon captures its intended use and operational design in military contexts.