Which weapon is fired from an open bolt position?

• A. M16A3
• B. M240B
• C. M2HB
• D. M500

Answer: (B)

Open-bolt operation is used in many belt-fed machine guns to help manage heat during sustained fire. In an open-bolt system, the bolt is held back after the previous shot; when you pull the trigger, the bolt slides forward, chambers a round, and fires, with the chamber exposed to air as the round is fired. This design helps dissipate heat and reduces the risk of cook-off, which is why it’s common on weapons built for continuous use. The M240B is a gas-operated, belt-fed machine gun designed for sustained fire and uses open-bolt operation, making it the weapon that fires from an open bolt. The M16A3 is a selective-fire rifle that is designed to fire from a closed bolt to enhance accuracy. The M2HB is a heavy machine gun that also operates from a closed bolt to maintain stability and precision. The M500 is a pump-action shotgun, not an automatic firearm, and does not use an open-bolt mechanism.