“f you look at the second video in the article, at the 13 second mark the weapon has 7 barrels, at the 33 second mark it has 6 barrels.” [Midwesterner53]
Then American Shooting Journal bungled - assuming they put the vid together.
The GAU-8 has always had 7 barrels. Any video footage with six barrels had to be of a different gun.
Powered Gatling Guns were experimented with circa 1900. All development rested there until the 1950s, when General Electric modernized it to produce a new powered gun for aircraft, the M-61 (nicknamed “Vulcan”). It was mounted on a number of aircraft, including F-4, F-14, F-22, F-104, F-105, F-16, F-15, B-52, B-58. US Army Air Defense Units used a version mounted on a tracked vehicle; US Navy used them to counter anti-ship missiles as part of the Close-In Weapon System.
GE produced a smaller gun in 7.62x51mm NATO, the M-134 Minigun. It was used in Southeast Asia on the AC-47 gunship and the A-37 attack aircraft. Flexible and turret versions have since armed various helicopters.
An experimental model chambered in 5.56x45mm, but he Army wasn’t interested.
The concept has been moodified over a range of barrel numbers and calibers: 3 and 4-barrel guns, the US 50-cal machine gun round (12.7x99mm Browning), some 25mm rounds.
The F-35 mounts the GAU-22, a four-barrel version in 25mm.
The Army used the 20mm round 6 barrel version because I had four of them in my platoon as a young 2nd LT. The Army also adopted what we called the mini gun, the smaller version strapped to helicopters using either 5.56 or 7.62. The Vulcan came in self propelled and towed versions, both now sitting in museums now.