FWIW, miniguns do use linked belts and fire the standard 4:1 ball/tracer mix. They use the same link (M27) as the M60, M240, MG3, etc. The belts travel through a feed chute to protect the belt from getting snagged - it moves quite fast through the gun, and if it gets snagged or drags on something, the rotor inthe gun will continue to turn and shred live rounds and brass (its a real mess - I've helped pull one apart after a belt got caught on an edge inside the feed chute and the rotor mangled about a dozen rounds inside the gun.)