MBA Gyrojets and Other Ordnance

[US-Subs]

New book out on MBA and their ammunition, the folks that brought you the Gyrojet, Lancejet, Finjet and Javette. I was given a copy to review last year, its an excellent work and well worth the money. For those not familiar with the Javettes and such, google the Church Committee Hearings and read how the CIA was caught in 1975 cheating on the bio weapons treaty - or buy the book. A picture from the hearings is attached, this is one of the electronically fired pistols used to fire the javettes. See the book and some examples of ammunition at the auther's website: http://gyrojet.net/

 

[HAZORD]

The gyrojet is one of few weapons, where the projectile actually accelerates as it is leaving the gun, so it is actually more lethal if you are a distance from your target. They can be seen in action in the James Bond movie "You Only Live Twice", being fired by Tanaka's Ninja army at their training site.

 

[V40]

In Plasters book, on page 161, a Lt.George K. Sisler earned his Medal of Honor, Posthumously by a sniper's bullet that killed him instantaneously. Then J.D. Bath, another Recon man who used a Gyrojet, 13 mm in size did an experiment.

They placed an old door from a three-quarter-ton truck in front of a 55 gallon filled with water. The round made a swishling sound in the handgun's barrel and then it was quite until it hiit something silent. Any how, it was fired and the round plowed through the door and into the the 55 gallon and it almost penetrated the other side leaving a large dent in it.

The Gyrojet used up all of its propellant in the barrel in approximately 100 miliseconds. With a resounding "Wooosh" which gave itself away, as it was supose to be a quite and silenced handgun. The gyrojet was also finicky and the accuracy just wasn't there, unless you were up close enough of a few meters.

 

[EODGUY]

Interesting comment about Bath's experience with a Gyrojet. It sure runs counter to my experience and the Army's experience with the system. The bullet, since it contains its own propellant does not have the space or the weight carrying capability to have an armor piercing core in it of any significant size. That was one of the major complaints of the Army when approached by Bob Mainhardt offering the weapon and ammunition for trials. The weapon also lacked down range velocity and was very inaccuate. A Mark I, Model B, 13mm Carbine was shipped from White Sands Missile Range to Aberdeen Proving Ground, Maryland in 1973. That was 7 years after the Army bought the weapon to test. They had conducted initial performance testing and performance was so undesirable they eventually sent it to Aberdeen to the Ordnance Museum for display before any formal test program had even been initiated. I personally fired both the carbine and handgun in 12.7mm caliber and my opinion was the same as the Army's. The initial weapons and ammunition were developed in 13mm size and that is what the government expressed interest in. That caliber ran afoul with the 1968 gun law though, and MB Associates, the maker, reduced the caliber to 12.7mm to be legal. Very few armor piercing designs were tested because of the lack of core capability. Those that were tested would only penetrate a very small amount of armor before losing velocity. The attached photo show a typical 12.7mm complete round with a rounded nose. Next to it is one I fired against a 1/16 inch steel plate at about 50 yards and you can see it flatttened out, dented the plate and fell to the ground with no penetration. Next to that is one of the armor piercing designs with a hardened steel tip, but again, it did not perform well. The last round is one I cut away to show the interior design and you can see that the rocklet grains occupies the interior of the projectile. The typical 12.7mm bullet had a burnout weight of 185 grains, a maximum velocity of about 1250 fps and developed about 700 foot pounds of energy at burnout, which occured in about 10 to 30 feet from the muzzle, not in the weapon itself, depending on the bullet design. While this about twice the muzzle velocity and double the energy of a cal. .45 Auto ball round it is about the same as a .357 magnun bullet. The 13mm bumped up to about 3000 fps at burnout and a little more than 1500 foot pounds. It is spinning at 200,000 rpm at burnout. The unfired 13mm ball bullet weighed about the same as the standard cal. .45 Auto ball bullet. None of these statistics, with a soft copper alloy jacket (hollow at that point) and no penetrating core will do much against steel plates or multiple sheet steel at respectible distances.
Like the Volcanic cartridge designed many years before, the Gyrojet was a curiosity, but not an effective weapon. The only effective use of the technology was the signal rounds in the Air Force pilot's survival kit. The small self-propelled flare bullets and the simple lightweight pen-gun launcher were perfect for that use. In this case accuracy was not an issue either.
Bob

 

[V40]

Also, if I can find it, which I am unable to remember where I put it. There is an article I have from a magazine that explains a little about R & D and results of accuracy and velocity. I will dig this article out and see what it says. I just remember it being wrote in great detail.

And by the way, he did not mention at what distance he was from the door?

 

[US-Subs]

The attached photo show a typical 12.7mm complete round with a rounded nose. Next to it is one I fired against a 1/16 inch steel plate at about 50 yards and you can see it flatttened out, dented the plate and fell to the ground with no penetration. Next to that is one of the armor piercing designs with a hardened steel tip, but again, it did not perform well. The last round is one I cut away to show the interior design and you can see that the rocklet grains occupies the interior of the projectile. Bob
View attachment 49357

Here are a few of mine. I just finalized a deal on a Javette round, cost me about the same as a nice M26 grenade would - but you don't get many chances for them.

 

[Anders]

Does any of you guys have a spare Gyrojet round that you want to sell?

 

[US-Subs]

Look at the link provided at the begining of thios thread, he has some other stuff as well.

 

[EODGUY]

Thought I would add some of my Gyrojets to the thead also. All sizes and shapes. Each set shows the profile and nozzle variations. Bob

 

[EODGUY]

Another grouping of Gyrojets, fin jets and javelins. The photo with the long arrow-like gyrojet has asignal gyrojet cutaway. Bob

 

[HAZORD]

Really nice stuff Bob!

 

[Anders]

Unbelivable, I had no idea that so many different variations existed, thank you for posting these photos.

 

[US-Subs]

Very nice Bob, I've been looking for some Javelins, but not much luck.

 

[V40]

I should mention that the first post I made was a mistake. It wasn't a truck so-to-speak. IT was a driver's door that was placed up against the 55 gallon, not the whole truck. Please forgive me for this error!

 

[Jolly Green]

WOW Bob! WOW!!!

 

[SG500]

Just a couple of photos of a recent addition to the collection.
The larger gyrojets seem to be hard to find on this side of the pond.
This ones a 25 x 147 one that's been fired.
Shown next to a standard 25 x 137 for scale.
All INERT.
Dave.