The United States Government designed the M29 mortar as a replacement for the standard Army and Marine Corps 81mm service mortar of World War II and the Korean War. The straight tube of the M29 was chosen as the best option for two reasons: range and portability. This mortar had a greater range than its predecessors and was also lighter, allowing for it to be a more portable weapon. The M1 weighed around 61.7 kg (136 lbs.), while the M29 weighed a considerably lighter 42.4 kg (93.5 lbs.). This lighter design allowed for it to be put into position quickly while also carrying more mortar rounds and could effectively engage the enemy at a further distance.

Many different projectiles were available for firing with the M29 mortar.

• M364 High-Explosive (HE) rounds were able to reach a range of 4,934 yards.

• M364A1 HE hit targets out to a range of 5,180 yards.

• M375, a general white phosphorous round, had a range of 4,934 yards.

• The M301A1 Illumination round burned in the sky for up to 75 seconds and hit a range up to 2,296 yards.

• This would illuminate an area of up to 1,200 yards.

In 1964, the United States Army and Marine Corps created the M29A1 as an improved version of the M29. The M29A1 featured a chrome-plated hard bore tube that allowed for an increased rate of fire and allowed for easier cleaning. Its chrome plating made it more resistant to battlefield wear-and-tear as well.