I have a friend (Captain pilot of AC-130 Spectre or Spooky, can’t remember) who was in PANG in Afghanistan, and he/his wife gave me a 105mm howitzer shell casing and clip of 4 40mm cannon shells. Still have them. I don’t know what the minigun can capacity was. As fast as they fire, 50k was probably not near enough.
My bother said thy had an M60 fed with a 50,000 round minigun ammo can. That was almost 50 years ago so I would expect improvements.
Gun trucks in Viet Nam had 50 caliber cans packed in the bed three layers deep. Kinda makes a 22 seem quite small.