Marines and Moldovan soldiers train together with anti-armor weapons during a live-fire familiarization workshop. Video by Lance Cpl. Ryan Young. Marines Train with Anti-Armor Weapons in Moldova I created this video with the YouTube Video Editor . Marines and Moldovan soldiers train together with anti-armor weapons during a live-fire familiarization workshop. Video by Lance Cpl. Ryan Young. The AT4 is an 84-mm single-shot anti-tank weapon used by the U.S. Marine Corps. It is designed to give infantry units a means to destroy or disable armoured .