What type of operating mechanism is used in the M-16A2 rifle?

The M-16A2 rifle utilizes a gas-operated mechanism, which is a type of system where the energy from the gas created by the burning powder in the cartridge is used to cycle the action of the rifle. In this system, gas is diverted from the barrel through a gas port into a gas tube leading to a piston or directly into the bolt carrier group, where it acts to unlock and cycle the bolt. This allows for semi-automatic or fully automatic fire, depending on the variant of the rifle.

Gas operation is preferred in military rifles like the M-16A2 because it results in reliable cycling and can maintain performance under various environmental conditions. The use of gas operation also reduces recoil, contributing to better accuracy during rapid fire, which is crucial in combat situations.

While other mechanisms, such as blowback and recoil operation, are used in various firearms, they do not apply to the M-16A2. Blowback relies on the mass of the bolt and the pressure of the cartridge to cycle the action, usually seen in smaller caliber weapons. Recoil-operated systems often involve a different form of energy transfer that does not utilize the gas from the barrel. Spring-powered mechanisms are typically found in air guns or toy firearms instead of military