The M16 rifle is a lightweight, air-cooled, gas-operated assault rifle that was first adopted by the U.S. military in the 1960s. It is known for its accuracy and high rate of fire, making it effective in various combat situations. The rifle typically fires the 5.56x45mm NATO cartridge, which contributes to its manageable recoil and allows for rapid follow-up shots. Over the years, the M16 has undergone several modifications and improvements, resulting in different variants. It has been widely used in conflicts around the world and has influenced the design of many modern firearms, including the M4 carbine, which is a more compact version used by current military forces.