Marine Corps Academics Officer Candidates School (OCS) Practice Test

LM-GAS breaks down five features that describe this rifle: Lightweight, Magazine-fed, Gas-operated, Air-cooled, Shoulder-fired. Each term points to a characteristic of the M-16A4 design. Lightweight means the weapon is easy to carry in the field. Magazine-fed indicates it uses a detachable magazine to feed rounds. Gas-operated refers to the action being cycled by gas tapped from the fired cartridge. Air-cooled means cooling relies on surrounding air rather than any liquid cooling system. Shoulder-fired shows the weapon is intended to be braced against the shoulder for stability and accuracy. While you’ll see slight wording differences in some sources (like shoulder-fire versus shoulder-fired, or weapon versus rifle), the essential meaning remains the same: Lightweight, Magazine-fed, Gas-operated, Air-cooled, Shoulder-fired.