Skip asked in the comments to yesterday's Plane Pr0n post: "...where do the empty shells go?"
I responded with the datum that they cycled right back into the ammuntion drum. But, since a picture is worth a thousand words, and a reader sent me some pictures yesterday - let us illustrate it! Note the two feed chutes. One feeds complete rounds out to the gun, the other routes the empty casings back into the drum, which has a helical structure inside, kind of like a drum-shaped vending machine full of sodas... However... the rounds don't spin in there. They're actually in channels that run longitudinally along the drum. The helix in the center spins, pushing the rounds forward in their channels, where they feed into a buffer mechanism that picks them up and starts them in the chute headed for the breeches. Larger version of the picture above available by clicking here. The GAU-8 also pioneered the use of large caliber aluminum casings, to save weight over the more conventional brass.
Here's a drawing showing the guts of the drum.
IIRC, live rounds feed from the front, while the empties feed back into the drum from the rear. Through some pretty clever mechanical and materials engineering, the gun itself only weighs 640 lbs or so. The whole thing together with a loaded ammuntion drum weighs in the vicinity of two tons.
H/t Glenn C for the VW pic.
This blog is a classic example of great minds thinking alike--Arty and CAS working in close concert to achieve the objective--an informed readership. Heh.
But that's cool. I'll just stand here offstage and bask in your reflected glory.
[Geez, did I actually say all that and still keep a straight face?]
Point 2: Oldloadr: As I understood the system when I was flying, the gun does indeed stop, back up AND then chambers the first round in the queue of live rounds, not to a fully cleared position. Otherwise, the response time at trigger pull would be longer. (This comes in handy on multiple bursts on the same pass.) So, in the air, releasing the trigger does all that on 1.5 seconds. You read that right--from ~3600rpm to 0rpm to unload to first barrel reloaded and ready--in a second and a half. Selecting OFF on the Master Arm switch electrically "safes" the gun even though there's to safety pin in. As a safety policy, however, that's why we don't do practice air-to-air with an unpinned gun. Once you land, the gun is manually backed up to unchamber that live round and then the gun is pinned before you taxi to parking.
What's kinda neat is that, after firing, as you're repositioning you'll hear and feel a "kerthunk!" as the 7 barrels are rotated sequentially for a few seconds to cool them in the airstream. If you look closely at the underside of the nose, you'll see the air scoop.
I was wondering what the comparison of kill ratios would be between the VW and the Hog. The Hog achieves a kill much more elegantly without damage to itself.
OTH, if Ted Kennedy had been driving a VW, he'd have ended up POTUS.
I hope this thing has a few more Safeties then our minigun. We also had to manually back up the gun to unchamber the "live" barrel. If you "back up" in the wrong direction, you'll get a definite, "Oopps". We came within a few inches of killing a Major one day while trying to unjam one of our mini's.
Whenever I've heard them fired it sounds like a gargantuan chainsaw.