After watching the Forgotten Weapons video about the AN/M2 "Stinger" machine gun a few weeks back, I've come to wonder why the US Military didn't try to adapt the M1919 into a GPMG. Army Ordnance clearly had the idea during WWII with the M1919A6, equipping the M1919A4 with a pistol grip and trigger, buttsock, BAR bipod, quick-change barrel (though I use that term loosely), and a muzzle-booster and flash-hider. You then have the 'Stinger,' though that was more a pet project of a Marine battalion based on the AN/M2 aircraft mounted thirty, and you also have the earlier LMG variants of the M1919A1 and A2.

The Army and Marine Corps continued to use the M1919A6 and the BAR well into the late 50s/early 60s, when the M60 finally came into service, and of course you had other potential GPMGs like the .30-06 MG-42 experiments and the FN MAG. However, looking at the M1919A6 got me thinking that even that design could have been improved without too much difficulty. The 'Stinger' weighed 25 lbs as compared to the A6's 32 lbs, thanks to the lighter components of the AN/M2 aircraft-mounted gun (lighter barrel, thinner receiver walls); of course the guns suffered from overheating due to their high rate of fire, closed bolt and lack of a quick change barrel, but both latter issues could be solved on the M1919. While the M1919A6's quick-change barrel could hardly be called that, as it required the removal of the flash-hider and muzzle-booster with a wrench so as to pull out the barrel from the front of the gun, as early as the Korean War Springfield Armory's design for what became the M73 coaxial tank machine gun, featured a quick change barrel system similar to that of the MG-34 and seems like it could have worked if adapted to the original M1919 design on which the M73 was based. As well, the .303 Browning Mk. II used by the RAF fired from the open bolt, which combined with a quick change barrel could solve the heating issue.

Having been made lighter and modified to better function as a GPMG, the only issue I could see would be finding an effective bipod for the M1919 GPMG, though with the M73's quick-change barrel you wouldn't need to remove the bipod as with the M60. Detachable belt-boxes had already been developed for the AN/M2 aircraft gun, and the US, Canada, Britain and various other countries modified their 1919s to fire 7.62 NATO in new belts the late 50s and 60s. Such a gun would probably be a Cold War design, but I'd be interested what effect such a weapon could have had if it had been developed via an earlier POD, and the effect this could have had on US infantry tactics during or immediately after WWII.