After looking at your top photo in a little more detail, I belive that it is the nose mount configuration of the M61/A1 for the F-18. Also an easy way to tell the difference between the 20mm and 30mm Gatlin weapons, 20mm=6 barrels, 30mm=7 barrels. That and the 20mm looks like a pop gun compared to the 30mm, the 30mm is truly artillery.
Pic of a AC-130 Spectre gunship hosing down some bad guys on a little vacation isle known as Grenada, October 1983. If you remember the video from the Grenada invasion, the buildings with all the neat little holes in them were from the AC-130s.
Pic of Puff, AC-47 gunship from Vietnam.
Pic of Puff's mini guns.
Crest of the 16th SOW, Hurlburt Field Fl., some of the brave men who fly the gunships.
Nose art on a AC-130U
Crest of the U.S. Air Force Special Operations Command.
16th SOW
AC-130 Gunship Info and pics