The Mark19 is a heavy [censored] too but the designers had no problem backpack mounting one with heavy as [censored] 40mm grenades as the ammo supply.
(IRL, a Mk19 with 30 rounds, and mind you no backpack or feed system, would weigh about 90 pounds. The only thing IRL close to the minigun is the XM214 which, with all of the "6-pack" components weighs about 75 pounds. A M2 gun only plus *without* any ammo, tripod or feed system weighs 84 pounds.)
Edit: Whoopsie. Bad math and logic. Mercy only holds 18 40mm for 9 weight units and a regular GMG hold 30 25mm for 7.5 weight units. Plus I though ammo weight was taken off when you loaded the weapon, but it is taken off when fired. So you can sorta ignore most of that nonsense above.
-Gunny out.
