The M29 series 81 mm mortar entered service in 1952. It consisted of three major parts: the tube, the base plate with an outer ring weighing 21 pounds and an inner ring weighing 24 pounds, and the bipod, which contained the M34A2 sight and four aiming stakes. It could fire 24 rounds per minute, and available projectiles included high explosive, general white phosphorous, and illumination rounds.