Dillon Aero, Inc. is the manufacturer of the Air Force GAU-2B/A (Army M134) 7.62×51mm minigun used primarily by 160th SOAR. The company has completely redesigned the weapon and significantly improved its reliability while reducing its weight. Its production facility is located in Scottsdale, Arizona.
The U.S. Government purchased about 10,000 miniguns during the Vietnam War. By 1975, the manufacturer ceased making spare parts because the Army possessed a large inventory, but by 1985, there were few spares left in inventory. Units could not maintain them, so by the 1990s only Task Force 160 and some Navy Special Boat Units kept them in regular use. Around 1990, Dillon Aero coincidentally acquired a large number of surplus miniguns and spares from a "friendly foreign user." Unaware of the U.S. Army's use of the weapon, Dillon Aero experienced continuous failures and determined that the surplus parts were worn out. Dillon identified the source as design-related and decided to fix the problems rather than simply put the parts into storage.
In 1995, the U.S. Army TACOM Life Cycle Management Command began acquiring spare miniguns for TF 160, but suppliers had a difficult time reproducing parts to the original specifications. The parts produced were unreliable. They were mixed in the spares inventory and caused weapons to randomly fail which led the 160th SOAR to consider dropping the weapon entirely. This would have ended its service life in the U.S. Military.
The 160th SOAR learned about Dillon Aero's efforts to improve the minigun design and invited them to Fort Campbell, Kentucky to demonstrate their products. Dillon Aero brought a delinker, used to separate cartridges from ammunition belts and feed them into the gun housing, which 160th SOAR needed. During 1997-2001, Dillon Aero was producing 25-30 weapons a year, including redesigned parts including the bolt, housing, and barrel. By 2002, they had improved virtually every component of the minigun, so Dillon began producing the entire weapon using their improved components. The Dillon miniguns were quickly purchased by the 160th Regiment, certified by TACOM in 2003, and designated as the M134D.
The M134D was a steel housing and steel rotor. Since 160th SOAR was their primary customer, Dillon Aero saw an opportunity to reduce the weapon's weight. They developed a titanium housing and rotor which reduced the design weight from 62 pounds (28 kg) to 41 pounds (19 kg). However, the titanium housing reduced service life to 500,000 rounds, which was higher than a conventional machine gun's 40,000 round lifespan, so Dillon Aero went back to a steel barrel. The change added only 1 pound (0.45 kg) to the weight but increased the service life to 1.5 million rounds. This hybrid, designated the M134D-H, is as of 2013 used by various 160th Regiment units.
Dillon minigun use
In addition to the weapon design, Dillon has improved specialized weapon mounts and ammunition-handling systems. Initially, they manufactured mounts for aviation systems. Then from 2003–05, the Navy began mounting Dillon miniguns on specialized small boats. In 2005, the Naval Surface Warfare Center Crane Division procured guns to mount on Humvees. Army Special Forces on the ground in Iraq mounted M134Ds on vehicles, where their extremely high volume of fire stunned insurgents and caused them to quickly break off attacks. The physiological effect of the minigun on enemy forces caused special forces to conceal their guns to trick them into attacking, while regular Army units began painting and tying together six sections of PVC pipe to make insurgents think they were armed with it to dissuade them from attacking.
Dillon is owned by Mike Dillon, owner of Dillon Precision, a manufacture of reloading presses and other reloading equipment.
- The Evolution of the M134D Minigun - Defensemedianetwork.com, 30 May 2013