Weapons: The 60mm Wonder Got Better

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May 26, 2012: The U.S. Army and the U.S. Marine Corps are beginning to receive the new M224A1 60mm mortar. This is an updated version of the original M224. Weighing 16.1-21.1 kg (35.4-47 pounds) the new weapon is a much awaited improvement on pre-M224 models. 

For ease of carrying the mortar breaks down into several components. The tube weighs 6.5 kg (14.4 pounds), the bipod is 6.9 kg (15.2 pounds), and the sight is 1.1 kg (2.5 pounds). There are two base plates. The standard one is 6.5 kg (14.4 pounds), the lightweight one is 1.6 kg (3.6 pounds). The older World War II era M2 model weighed 19.05 kg (42 pounds). A less successful World War II era model, the M19, weighed 23.4 kg (52 pounds).

Some of the M224 technology arrived early. Four years ago a new mortar tube was introduced for the 60mm and 81mm mortars. New metals (Inconel 718 alloy) and manufacturing methods (flowforming) reduced the weight of these mortar tubes 30 percent, and increased the robustness. But the lighter tube only reduced the overall system weight about ten percent. The complete M224 system reduced overall weight 20 percent. A year after the M224 was sent to some units for field tests, a few minor tweaks were made, resulting in the recently introduced M224A1.

For the infantry, however, every pound counts. So the M224 was particularly welcome. But the troops were very pleased at how the lighter M224 actually performed.

The marines and the army use the 60mm for infantry companies (each of three infantry platoons, plus a heavy weapons platoon), giving the company commander his own artillery. Modern 60mm mortar shells, which weigh about 1.6 kg (3.5 pounds) each, have a range of 2,000-3,500 meters. For many decades the max range of 60mm mortars was more like 2,000 meters. The M224 can use a longer range (3,500 meters) round. The longer range shells, and the availability of mini-UAVs at the company level, make the 60mm mortar a much more potent weapon. The UAV can spot targets behind hills or buildings and then adjust the mortar fire until the target is destroyed.

Infantry mortars were invented during World War I (1914-18) but have been largely unchanged since then. The current U.S. mortar designs were introduced in the 1980s, but the new tube, longer range ammo, and guided shells (in larger calibers than 60mm) are rather recent developments.