|Caliber:||.50 inches (12.7mm)|
|Length:||11 feet 2 inches|
|Height:||3 feet 8 inches|
|Shell:||106×607mmR (HEAT, HEP, HEAP, Canister)|
|Muzzle Velocity:||1,650 feet/second|
|Manufactured by:||Watervliet Arsenal|
|Owner:||Estrella Warbirds Museum|
The M27 recoilless rifle was a 105-mm weapon developed in the early 1950s and fielded in the Korean War. Although a recoilless rifle of this caliber had been a concept since the Second World War, the weapon was hurriedly produced with the onset of the Korean War. The speed with which it was developed and fielded resulted in problems with reliability caused by trunnions that were mounted too far to the rear. The M27 was also considered too heavy by the U.S. Army and had a disappointing effective range due to the lack of a spotting rifle. Taking the M27 as the basis for a new design, the Army developed an improved version of the M27 that was type-designated the M40 106-mm recoilless rifle in 1955. Originally, along with its type-designation, it was also given the official name BAT for Battalion Anti-Tank gun, but that was soon dropped. Although unsuitable for military purposes, M27 recoilless rifles were used to trigger controlled avalanches at ski resorts and mountain passes in the United States.
The M40 primarily saw action during the Vietnam War. It was later replaced by the BGM-71 TOW anti-tank missile system.