A 105mm recoilless rifle developed to replace the M18 and M20 recoilless rifles, which proved to struggle against enemy tanks during the Korean War. The M40 saw combat action during the Vietnam War and was used by both sides in the 1971 India-Pakistan War.
It is most famously depicted as the main armament for the M50 Ontos, which mounted six of the weapons.
The M40 and recoilless rifles as a system were replaced by anti-tank missiles such as the BGM-71 TOW.
