US 81mm Mortars

The M1 Mortar was a 81mm (8.1cm) infantry mortar used by the United States in World War II. It was phased out of service in the 1950s by the M29, which was lighter.

IRL

The M1 Mortar was the american version of the Brandt Mle 27/31 mortar, a highly influential mortar system for the allies. The M1 weighed 136 pounds, making it highly mobile compared to some of the other axis weapons they faced. It had could kill fascists from almost 2 miles away (3 kilometers, for you Europeans), and typically launched anything from 6 lbs of light HE to 10 pounds of white phosphoric death upon any unfortunate bastard to get caught underneath its fire.

The M1 was so successful that it was compared to be either superior or equivalent to some Howitzers fielded in the armed forces, such as the 75mm howitzer of the 105mm Howitzer.