GAU-19 Gatling .50 Cal

The GAU-19 Gatling .50 Cal is one serious piece of hardware which I thought I’d mention today in light of it’s renewed interest for Naval deployment.  Many have never even heard of it or seen it deployed, which is a shame because this monster can lay down the hate.  Whenever someone is talking about the .50 Cal BMG round, you just know it’s going to be some serious firepower being laid out.  Normally the .50 Cal BMG is associated with the M2HB heavy machine gun.  With growing piracy threats and the increased threat of waging war with Iran and their many small boats such as the old Boghammar and copies, the GAU-19 is gaining popularity as an effective defensive weapon to counter the small-boat threat.

The GAU-19, or Gun, Aircraft Unit-19 was originally designed to be utilized as the forward gun turret for helicopters (commonly referred to as the ‘chin’ gun) such as the AH-1 Cobra (The AH-1 utilized the M197 instead).  General Electric designed the weapon in the late 70s and it first saw service in 1983 under the designation GAU-19/A.  The system was once designed as a beefed up copy of the M134 7.62x51mm Minigun, complete with 6 barrels and firing the much larger .50 BMG cartridge.  Later on during testing it was decided the 6 barrel system depleted the systems magazine too quickly and added too much weight to the already large weapon, so a 3 barrel prototype was developed.  The 3 barrel version was smaller, lighter, and didn’t deplete ammunition as aggressively.

The GAU-19 has seen little change made to its design since entering service.  It is still relatively unknown to the majority despite the impressive firepower it can deliver and General Dynamics now seek to see it adopted in more roles than the original design as a Helicopter only weapon.  General Dynamics created a more diverse set of mounting options in hopes to attract more sales of the system.  There are now aircraft external mounts (pods), aircraft crew mounts, vehicle mounts, and surface ship mounts available.  A recent version has been released, the GAU-19/B, which reduces the system weight and is optimized for vehicle or patrol boat usage.  With the newer system, interest is growing in the Naval Mount version in particular as a small boat defensive weapon.

The system operates very much like the 7.62mm M134 Minigun system in being electrically driven and mechanically fired.  When the system is firing, a feeder/delinker is spun by the systems drive motor and strips the ammunition out of the belt before handing it off to the actual gun portion of the weapon.  Think of it like a cars serpentine belt.  The drive motor rotates the gun, and in turn rotates the feeder/delinker as well.  The ammunition feeds into the weapon as it rotates, and the 3 bolts are following a guide cam on the gun housing.  The guide cam drives the bolts forward and rearward to perform chambering, locking, firing, and then unlocking, extracting, and ejecting in a wide elliptical motion.  When the bolt is in its forward most point, compression releases the firing pin to discharge the round and is re-cocked as it is pulled rearward.   Specifications for the system are as follows:

  • Gun Weight: 138 lb for GAU-19/A or 106 lb for GAU-19/B
  • Rate of Fire:  1,000/1,250/1,300/2,000 rpm for GAU-19/A or 1,300 rpm for GAU-19/B
  • Magazine: 900 rounds (HMMWV), 1,200 rounds (Naval), 500-1,200 rounds (GAU-19/B)
  • Recoil Force:  495 lb @ 1,300 rpm (GAU-19/A HMMWV or Naval), 575 lb @ 1,300 rpm (GAU-19/B)
  • Effective Range:  2,000yds (1 Nautical Mile)
  • Max Dispersion:  5 mrads (80% circle) = 5m @ 1000m

There is a wide variety of ammunition available for the .50 BMG cartridge.  The GAU-19 system can utilize any available linked .50 BMG ammunition from standard ball and tracer, Armor Piercing Incendiary-Tracer (API-T), API-Dim Tracer, or the advanced Mk 211 variety rounds which I would encourage the use of for naval units.  The Mk211 and Mk257 rounds have been called Raufoss rounds by some since that was the name of the Norwegian city the rounds were first produced in and has been nicknamed as ‘Christmas Tree’ in some NSW circles due to the green, red, and aluminum paint markings on the tips of the linked rounds.  In technical terms, it is a High Explosive Incendiary, Armor Piercing (HEIAP) Tracer (Mk211) or Dim Tracer (Mk257).  I absolutely love this round, it makes nice big pop’s on target, often setting fires, and it makes a mess wherever it hits throwing out a 30° cone of fragmentation.  It is packed with 1 gram of RDX Comp-A Explosive for a filler, topped with .6 grams of zirconium for incendiary effect, and is pyrotechnically initiated after impact by the tungsten carbide armor piercing penetrator.  Mk211 Mod 1 (Grade B) is for machine gun use only, while Mk211 Mod 0 (Grade A) is meant for sniper applications due to being manufactured to a higher quality standard.  A video describing the round in use in a sniper application is at this link.

Regular Tracer on Night Vision

Firing Dim Tracer on Night Vision

In case you are wondering what a ‘Dim Tracer’ is, it is a special tracer which burns in the infrared spectrum and is invisible to the naked eye, but visible when using Night Vision Devices (NVD’s).  It produces less ‘white-out’ for gunners with NV Goggles on.

 

With the variety of mounts available for the GAU-19 it is receiving a more serious look for employment, primarily for the Navy as mentioned before.  The system when firing at 1,300 rounds per minute is firing 21 rounds per second and 7 rounds per barrel in that second.  If you have ever fired the M2HB, with it’s cyclic rate falling between 440-550 rpm its roughly shooting about 8 rounds in a second versus the 21 rounds from the GAU-19.  The GAU-19 can sustain fire for about a minute from its 1,200 round magazine, while the M2HB is usually holding about 200-250 rounds in it’s can on patrol boats.  Anyone who has shot the M2HB aggressively also knows that trying to empty 200-250 rounds in one burst will likely result in the weapon failing or cooking off.  The increased fire rate of the GAU-19 helps to get gunners on target faster and achieve more target impacts much like the M134 Minigun systems theory of employment.  The faster rate of fire means more rapid visualization of tracers and round impacts to drive the weapon onto the target with.  Against boats, the GAU-19 can devastate a craft if paired with the Mk211 rounds which have the potential of penetrating engines and setting fuel ablaze. 

In the video above you might have noticed a sudden increase in fire rate while shooting.  That was the gunner switching from 1,000rpm to 2,000rpm.  To wrap-up this article, I do hope the system becomes more widely adopted in our own service.  While it does have some shortfalls, such as it needing a reliable 24 VDC power source to power the drive motor or the competing availability of other weapons such as 20mm chain guns, I do believe that for a manned weapon this system holds it’s own against the competition being a relatively easy system to maintain in good service compared to the competitions weapons systems.  In the threat of suicide boats or against Iranian Gun Boats this system could allow rapid engagement and destruction out to a nautical mile with common ammunition and without needing major structural changes to emplace.  Training for gunners and armorers is fairly easy and the overall system cost is low and comparable to the M134 Minigun.  Why the system hasn’t seen wider adoption is beyond me, I’ll just have to wait and see I guess.

Bravo One, Out.

33 comments
DuyMinhAnDuong
DuyMinhAnDuong

BravoOne, Thank you very much for sharing.  I'm not quite sure if there's a general comment box for request or I've missed every time on the homepage. But I was wondering if you could do an article about a suggested Bug Out Bag loadout?

Tango9
Tango9 moderator

Every time I roll past this post I think:  "1 minute on that would be a great christmas present!"  Lord how I'd love just 1 minute...

katgirl
katgirl

Nice piece of hardware!  When I first heard about the Somalian pirates I thought I would love to see an experimental Minigun in .416 Barrett.  Long reach.  Not as much vibration for the az/el.  Lack of standardization and types of rounds though oh well.  I'm odd enough that when I watch FLIR videos of Apache 30mm runs, I notice all the glowing floppy pieces flying around.  Here's a closer view of what I bet is HEIAP hitting an insurgent viewed about as close as you can get on a thermal IR monitor which this spotter gets to use.  http://www.military.com/video/operations-and-strategy/afghanistan-conflict/sniper-hits-insurgent-with-50-cal/1101187478001/  I've been trying to figure out how to download it so I can slow it down, but this website is smart.  None of my tools can catch it.  That GAU-19 is hott.

ColonelProp
ColonelProp

Bravo One - is this a more reliable variant of the M-197 (20 mm 3-barrel Gatling) from GE? It struck me right off in your first photo like the photos I have seen of the XM-197 sticking out of the side of AU-24A Helio Stallion gunships from Cambodia. Just wondering is all...

SEAN SPOONTS(MAFIA)
SEAN SPOONTS(MAFIA)

Big confidence builder in taking that sucker out on an operation or flight. I was pretty happy with an M-60 in the door of the helo I crewed in, but that GAU would be something else. You could sink a surfaced submarine with it.

BoxOfGridSquares
BoxOfGridSquares

When 0331's dream of heaven this is what they imagine....

 

 

GoNavy
GoNavy

Would love to have one of these when SHTF on 12/21/12 :) :) Awesome firearm. Hate to be the end of the barrel on this.

Brent Okuley
Brent Okuley

Absolutely awesome firepower. This is the first time I've ever heard of a .50 cal minigun type weapon system. I was hoping to see video which I was rewarded with at the end of the article. The force of the recoil pushing the suspension of that HMMWV is impressive to say the least. 

Old PH2
Old PH2 moderator

Is General Dynamics working on a stabilized mount for Boat gun tubs?  I recall that this was one of the issues that the SWCC community were hoping to address.

 

Doesn't the CROWS system use a version of the GAU-19?

ColonelProp
ColonelProp

Holy Smokes that is one seriously cool weapon. I have got to save my pennies....... Thanks for the great write up Bravo One - I did wonder about the reliability with that big cartridge at high rate but it looks like it is not an issue. The 50 BMG looks like a very long term great design - a true masterpiece. My eyes just rolled back in my head - like feeding chocolate to a chocoholic....

SEAN SPOONTS(MAFIA)
SEAN SPOONTS(MAFIA)

@Tango9 "1 minute on that would be a great christmas present!" Lord how I'd love just 1 minute... I've been away for a day or so. Are we still talking about the gun?

katgirl
katgirl

 @Tango9 A photo of that would show only the GAU firing and a huge grin?

BravoOne
BravoOne

 @katgirl ...what you see there is classic internet mislabeling... That's a CROWS system with a Mk19 mounted, firing the standard 40mm HEDP (High Explosive Dual Purpose).  I'm looking to upload some videos for a future article with some Mk211 and Mk257 impacts to give an idea of what it's doing on target.

BravoOne
BravoOne

 @ColonelProp I'm not an air guy so I'm a little out of water there.  I can tell you that the M197 was developed before the GAU-19, and isn't as accurate either.  The GAU-19 is a fairly robust system, and has a pretty good reliability as long as the gunner sets it up correctly prior to firing so I would imagine the same applies on the M197.  For both the GAU-19 and Minigun both need to be set up and fired correctly or you'll get a nasty jam on the first shot and I'll tell you, they can be a pure bitch to clear.

BravoOne
BravoOne

 @Old PH2 I'm not certified on the CROWS so I can't speak for it, but I am certified on the Rafael Mini-Typhoon (Mk49 ROSAM) and it does have the capability to field the GAU-19.  USSOCOM uses the Mk49 ROSAM on NSW RIB's and Mk 5 boats, and Riverine's use it as well on RCB's (Riverine Command Boat's).  Too bad for us, the powers that be have not purchased or fielded the cradle required to mount anything but a M2HB.  One point I am very unhappy about with NSWC Crane and hoping they will get us that ability ASAP.

Tango9
Tango9 moderator

 @BravoOne Wow, looking forward to it Bravo One. 

katgirl
katgirl

 @BravoOne Thank you.  I was amazed how much the impact looked like a single 30mm from an Apache and was also wondering how the observer was able to carry such a big piece of equipment (FLIR) there.  Just looked it up.  Nice weapon system.  I wondered how 1gm of RDX would do that much :)

ColonelProp
ColonelProp

@BravoOne Thanks for the input! I believe, but gotta go dig in my files, the AU-24A had the prototype XM-197 and the initial assessments had some complaints. I have never dug up the action reports (I think most of the pilots were contractors). I wonder if this weapon was a response to issues seen. I can not even imagine having to clear one under fire.

Old PH2
Old PH2 moderator

 @BravoOne So who do I have to send Hookers and Scotch to for you boys to get what y'all need?

JackMurphyRGR
JackMurphyRGR moderator

 @BravoOne I got certified on the CROWS I and II.  As of 2010 you could only mount a M2HB or a Mk19. 

katgirl
katgirl

 @BravoOne omg yes!  Like the US soldier who tried to put a Japanese 'knee mortar' on his thigh!

SEAN SPOONTS(MAFIA)
SEAN SPOONTS(MAFIA)

@BravoOne @katgirl Yeah, lol. When I saw that Hummvee rocking I was reminded that the recoil force on JUST ONE of those rounds in on the order of 500 foot pounds.

BravoOne
BravoOne

 @katgirl I had a guy downrange call me up on the sat-phone to ask if he could delink and shoot the high velocity Mk19 rounds through the M79's we had...I wanted sooo badly to just smile and tell him to go ahead but I'm pretty sure higher would have crapped on me hard had he broken his shoulder while deployed...Never never never put a high-velocity round into a M79/M203!  They work the same, but one pushes back a LOT harder.

katgirl
katgirl

 @BravoOne The M430A1 HEDP is a terrific design.  Had do do some real digging to find some obscure info, but it uses the same high-low pressure system as the old Bloop Gun to propel it (lots faster).  The explosive charge design just blew me away (tee).  37gms of A-5 (pure RDX with a 1.5% stearic acid coating).  Sure does the job!

katgirl
katgirl

 @BravoOne I did some digging and found some good info on that system which I'll add to my page.  I saw a photo of a soldier in a Humvee in front of the monitor and joystick and it's sure the one.

Old PH2
Old PH2 moderator

 @BravoOne We'll start a collection and do this right.  Where can I get some Cuban cigars?