Which gas mechanism describes the FN FAL system of operation?

Which gas mechanism describes the FN FAL system of operation?

• A. Gas piston, long stroke
• B. Direct impingement
• C. Gas operated, short stroke
• D. Gas Tappet, select fire

Answer: (D)

Gas-tappet operation drives the FN FAL. Gas from the fired cartridge is tapped into a small tappet in the gas system, which transfers that pressure to move the operating mechanism and cycle the bolt. This setup differs from direct impingement, where gas acts directly on the bolt carrier inside the receiver, and from a short-stroke piston, where a separate piston only travels a brief distance. Many FAL variants include a selector for semi- or full-automatic fire, so describing it as gas tappet with select-fire fits both how energy is transferred and how fire modes are chosen.

Gas-tappet operation drives the FN FAL. Gas from the fired cartridge is tapped into a small tappet in the gas system, which transfers that pressure to move the operating mechanism and cycle the bolt. This setup differs from direct impingement, where gas acts directly on the bolt carrier inside the receiver, and from a short-stroke piston, where a separate piston only travels a brief distance. Many FAL variants include a selector for semi- or full-automatic fire, so describing it as gas tappet with select-fire fits both how energy is transferred and how fire modes are chosen.