BTDT... It'd be interesting if they could just whup up a gravity feed, kinda like the Dillon case feeders...
I mean, even cutting the thing down to 360rpm, you've got serious "keep their heads down" attitude going. Let's see...
What does 5,000 rounds of .22LR weigh? Figure 25,000 rounds/hour/gun, continuous. I've seen those pallets at Knob Creek... You could put a LOT more than 8 hours of semi-continuous suppressive fire on a single pallet. Of course, it'd be fun to engineer a barrel/rotation system that could handle that... I'm guessing accuracy wouldn't be the forte...
If your folks inside the wire don't have to worry about folks charging the wire, they can spend a lot more time on what they _really_ need to do- play "what if" with air support.