M134-D: THE DILLON AERO MINIGUN PACKAGE

SAR Staff — Sat, 01 Feb 2003 02:18:00 +0000

By Dan Shea

As readers of SAR are aware, for many years we have been following the design and modification changes of the M134 Minigun that Mike Dillon and now his company, Dillon Aero, Inc, have been working on. Dillon Aero has recently signed a $25 million dollar contract for supply of their system to the US military. This is an ongoing, five-year contract. Chris Dillon took the time to go through the modified gun from top to bottom with us, and SAR is pleased to present a brief overview, and then proceed to the detailed photo comparison of the new products to the old. I have participated in numerous tests of the Dillon Aero modifications, and was truly impressed with the reliability that they have brought to this system. The Minigun is finally coming into its own in the form of the M134-D; as one of the best tools for the military to inventory for defensive/ rescue and just plain “Everybody get the Hell off my Helicopter” guns. Dillon Aero’s M134-D’s work! – Dan

Mike Dillon has been working on Miniguns for twenty years. While these are a personal passion for Mike, he realized that the M134 guns just had too many problems to stay in most active military inventories. Mike worked on his own guns, with a mind to solving the problems. First, he had to identify where the majority of malfunctions were, and that was in feeding. These problems can be broken into two basic parts, the ammunition storage container with its interface to the feed system, and secondly the delinker-feeder.

Bryce Hatfield feeds a multi-thousand round belt up into the Huey for Mike to feed into the Dillon Aero magazine. Photo by Dan Shea.

Mike Dillon works on a new invention, a water cooled minigun. Photo by Dan Shea.

It has been over 30 years since the M134 ceased being a production offering, and spares and replacement parts have become hard to find. This was part of Mike’s inspiration of course, getting good reliable parts to keep his own guns running. In the course of that quest, Dillon Aero Inc was born, and Dillon gradually began to manufacture all of the parts for the M134 after improving them, and finally set his sights on making complete firearms and systems. His current projects include lightening the entire system even more. Those familiar with the rotary winged aircraft (“Helicopters” to our readers in Jersey) realize that removing even a few pounds can make a tremendous difference in the ability of that craft to fulfill its mission. Every pound you save translates into more ammo or fuel you can carry. With that in mind, we have included the full specs on the M134-D offering from Dillon.

In the photo caption text, we have tried to give a thorough look at Dillon Aero’s innovative solutions to these problems, and the other solutions they arrived at during the course of testing and firing millions of rounds of ammunition.

Military users of the current M134 Minigun should consider either completely upgrading their systems to the M134-D configuration, or replacing their aging systems with the Dillon offering.

SAR’s Technical Specifications for the M134-D Minigun:

Manufacturer:     Dillon Aero, Inc
    8009 E. Dillon’s Way
    Scottsdale, AZ 85260 USA
    Phone: 480-444-2919
    Fax: 480-948-6616
    Website: www.dillonaero.com
Caliber: 7.62x51mm NATO
Overall Length: 80.16 mm – 31.56 inches
Barrel Length: 55.88 cm – 22 inches
Weight, Gun: 15.75 kg – 35 pounds
Weight, Drive Assembly, 28VDC, AC: 3.60 kg – 8 pounds
Weight, feeder/delinker: 4.57 kg – 10.16 pounds
Weight, Gun Control Unit: 1.87 kg – 4.16 pounds
Weight, cables: 1.12 kg – 2.5 pounds
Weight, Battery: 13.61 kg – 30 pounds
Total system weight: (Less battery, ammunition and mount): 27.44 kg – 60.98 pounds
Feed system: metallic disintegrating linked ammunition belt
Number of Barrel grooves: 4
Direction of twist: Right Hand
Rate of twist: 1 turn in 25.4 cm – 1 turn in 10 inches
Firing Modes: full auto only, clutched
Rate of Fire: 3,000 RPM
Method of operation: external, electrically driven
Lock up method: cammed lock up
Acceleration time: 0.5 seconds
Deceleration time: 0.25 seconds
Power requirements: 28 volts DC, AC is available, DC volt requires 40 amps
Barrel life: 250,000 rounds
Reliability: 500,000 MRBF (Mean Rounds Between Failure)
System life: 1,500,000 rounds
Gun life (before rebuild): 1,500,000 rounds
Recoil forces (At 3000 rpm) Average: 90.72 kg – 200 lbs

Left- original feeder/ delinker end plate Right- Dillonís new version. On the Dillon end plate there is a ìSLAPî Snail path. This controls the motion of the cartridge case at the neck, instead of at the base. This avoids problems with non traditional cartridge feeding, including SLAP, blank or other unusual configurations. (Dillon Aero photo).

Original Stripper, push rod guide and drive gear.

Left: Original Rotor Assembly. Right: Dillon Aeroís newly designed lightweight Titanium Rotor Assembly. Dillonís offering is not only lighter weight, it is much easier to manufacture and has replaceable locking lugs. (Photo by Dan Shea)

Dillon Aeroís new narrow profile booster motor setup is compact and mounts within the planes of the ammunition feeding device. Anyone who has been in a helicopter knows that space is at a premium, and this seemingly simple improvement is actually more significant than it might appear, allowing for more compact storage of the feeding system.

Left: Original bolt face, arrow shows one major problem area. This area of the extractor lip is a major failure area. Right: The new Dillon bolt reduces the height of the right extractor by 0.080î. The new bolt is also contoured to prevent off-center firing pin strikes, and the new Dillon Aero firing pin has a spherical end to eliminate punctured primers. (Photo by Dan Shea)

Two pins are compressed against spring tension. This contains the system parts instead of potentially losing a pin, and allows for quickly popping open the safing sector (Photo by Dan Shea)

Left: the original barrel clamp had a separate flash hider as an afterthought. That flash hider was a cast unit, very heavy, and is not shown. Right: Dillon Aeroís new one piece, simplified titanium barrel clamp/ flash hider unit is not only a weight savings, it is a much more effective flash hider.

The seven pushers in the feeder/ delinker have been redesigned to reduce drag, be more stable in motion, and retain lubrication. Left: Dillon Aero pusher. Right: Original (Photo by Dan Shea)

Original bolt assembly showing the ìTripî at the rear that must travel in a channel in the rotor. Right: Dillon Aeroís new design where the firing pin is internally tripped, simplifying the process and making it more reliable. (Photo by Dan Shea)

Round repositioner that mounts on the Dillon Aero ammunition cans. Essentially, the belt feeds through it and the device ensures that all rounds and links are correct for feeding. Just one more way to keep from having feed problems.

The original booster motor assembly that helped feed the belts into the chute system were awkward and took up space outside of the magazine area. Dillon Aeroís new narrow profile booster motor setup is compact and mounts within the planes of the ammunition feeding device. Anyone who has been in a helicopter knows that space is at a premium, and this seemingly simple improvement is actually more significant than it might appear, allowing for more compact storage of the feeding system.

Rear: Original Bolt and carrier assembly, note the single locking/ unlocking tang. Front: Dillon Aeroís new bolts feature dual locking/ unlocking tangs, increasing reliability and reducing breakage. (Photo by Dan Shea)

Left: Dillon Aeroís new, simplified top cover and safing sector is a one piece assembly, and much easier to use. Right: the original assembly in its component parts. (Photo by Dan Shea)

inspections are much easier- to flip open the top cover on Dillon Aeroís M134D upgrade, there is a simple slide- much easier than the old pin system. (Photo by Dan Shea)

Left: The ìOldî way to have a gun control unit and motor. Right: The “Dillon” way- the new Dillon Aero GCU is compact, simplified, and mounts right to the spades.

This article first appeared in Small Arms Review V6N5 (February 2003)

M134-D – Small Arms Review

M134-D: THE DILLON AERO MINIGUN PACKAGE