At 41 lbs for gun and tripod, the M1919A4
was much lighter than the water-cooled M1917A1
(93 lbs for gun and tripod). On the other hand, the air-cooled weapon was
unable to maintain the same level of sustained fire as the water-cooled
M1917A1, and did not have the steadiness of accuracy as the heavier weapon.
Also, some combat units criticized the A4 as being too slow to get into
action, and that the crew was too vulnerable.
The result was M1919A6, which featured a detachable shoulder stock,
folding bipod, carrying handle, and a lighter barrel than the A4. Although
only 43,500 A6s were produced in WWII, compared to 390,000 A4s, and although
the A6 was even less steady in sustained fire as the A4, some experts argue
that the A6 was the most unique weapon in the M1919 series.
The M1919A6 did see some service in Korea, and later in Vietnam.
1919A4 and 1919A6 in Vietnam