The M242 is an electrically powered, chain driven, automatic weapon. It can destroy lightly armored vehicles and aerial targets such as helicopters and slow-flying aircraft. It can also suppress enemy positions such as troops in the open, dug-in positions, and built-up areas.

The M242 is fed by a metallic link belt and has dual-feed capability which allows the crew to select and load two types of available service ammunition. The M242 fires both European and U.S. 25mm ammunition. The five basic U.S. rounds used with the M242 include the M791, M792, M793, M910, and M919.

The gun can be installed or removed in three parts:

• Receiver assembly. 94.8 lb (43 kg).

• Barrel assembly. 89.9 lb (40.8 kg).

• Feeder assembly. 57.8 lb (26.2 kg).

The M242 is the primary armament on the U.S. Army M2/M3 series Bradley Fighting Vehicle and the U.S. Marine Corp LAV-25.