M1919A4 .30 Caliber Air Cooled Machine Gun. The air-cooled 'A4 was much lighter and more portable than its M1917A1 water-cooled counterpart.
Fully automatic, recoil operated, air-cooled
.30 (7.62 mm)
Ball M1; 174 gr bullet, 50 gr charge (.30-06)
853.4 mps (2800 fps)
18.5 kg (41 lbs) with tripod
104.1 cm (41 in)
Rate of fire
400 to 550 rounds per minute
1000m (1100 yds)
Before the end of World War I, the U.S. Ordnance Department recognized that water-cooled machine guns took up too much space inside a tank. Consequently, the water-cooled M1917 was converted to an air-cooled model by surrounding the barrel with a perforated metal jacket. As World War II approached, the Ordnance Department was committed to developing an air-cooled machine gun for infantry use. The result was the M1919A4.