The 75mm Pack Howitzer M1 (also known by its post-war designation M116) was designed in the United States in the 1920s to meet a need for an artillery piece that could be moved across difficult terrain. The gun and carriage was designed so that it could be broken down into several pieces to be carried by pack animals. The gun saw combat in the Second World War with the United States Army (primarily used by airborne units), with US Marine Corps, and was also supplied to foreign forces.
In addition to the pack / air portable configuration, the gun was mounted on a conventional carriage to serve as a field artillery piece. Derived vehicle mounted howitzers M2 and M3 were used in the 75mm HMC M8 and some LVT models. In addition, the M1 in its original version was mated to a number of other self-propelled carriages, though only one of those – 75mm HMC T30 – reached mass production.

Produced - 1927–1944
Number built - 8,400
Specifications
Weight - 653 kg (1,439 lbs)
Length - 3.68 m (12 ft 1 in)
Barrel length Bore: 1.19 m (3 ft 11 in) L/15.9
Overall - 1.38 m (4 ft 6 in) L/18.4
Width - 1.22 m (4 ft)
Height - 94 cm (3 ft 1 in)
Crew - 6 or more
Caliber - 75 mm (2.95 in)
Breech Horizontal block
Recoil Hydropneumatic, constant
Carriage - Box trail, dismantling
Elevation - +5° to +45°
Traverse - 6°
Rate of fire - 3–6 rounds per minute (sustained)
Muzzle velocity - 381 m/s (1,250 ft/s)
Effective firing range - 9,600 yards (8,778 meters)