How to reserect Gyrojet...

[Lo.Com.Denom]

The question about the MBA Gyrojet got me thinking... What would it take to un-:cuss: this design? So rather than hijack that thread, here are my thoughts...

Make sure that the round reaches all-burnt as it leaves the muzzle. Forget those silly nozzles -- make the back end open-up like the crimp on a blank cartridge and give it polygonal rifling. Give it a driving-band around the middle to engage the rifling and to stop it slipping down the barrel. To keep things "futuristic", let's give it electronic ignition with a filament-wire somewhere in the round. (Haven't figured out how to stop the filament blowing back into the mechanism yet, but it can't be too hard.)

Since the nose isn't going to touch the rifling, let's make it out of hardened steel and give it the profile of one of those "radially dynamic projectiles", to reduce over-penetration and make it military-friendly.

Make it .45 to .50 caliber, just because many people, rightly or wrongly, prefer a big-bore to a small one. No other reason.

Give it a break-open barrel for unloading and removal of malfunctioning rounds. Since the round will be held in place between the driving-band and the breach face, it should just drop out freely. Perhaps some sort of magnetic cartridge-remover, for sticky rounds?

I've got a locking system in mind which might just work, but, so far as I know, it's untried and untested by anyone else. No I ain't going into details here -- suffice to say that it should take care of obturation problems (*cough* if it works *cough*). I should probably patent it, but I'm sure that someone, somewhere has got there before me and done nothing with it.

There's plenty of other bells and whistles that could go on it, but them's the basics. No it won't be Earth-shatteringly better than any other .45 handgun, but that's not the point -- the SAA wasn't Earth-shatteringly better than cap-and-ball revolvers either.

So, have I missed anything? Any glaring, monumental errors? Anything to add to our "Future-pistol"?

Lo.Com.Denom

[Bluehawk]

Forget those silly nozzles -- make the back end open-up like the crimp on a blank cartridge and give it polygonal rifling.
Unfortunatly rockets don't work that way...you have to have a nozzle(s) restriction...either at the sides like the original to spin stabilize the round or at the back...to just open up the back doesn't give it any thrust! The nozzle has to converge and diverge in order to work.

[Car Knocker]

If the filament were light enough and cast in the propellant, it would be consumed in the firing. Build a battery into the magazines to power the electronics and and ignition systems, and to perform continuity checks on the ignition filaments (think green light/red light on each mag, activated with a pressure switch) before insertion.

A tip-up design may allow a spring-powered chamber insert that would eject chambered rounds, spring to be cocked by barrel opening/closing.

There's going to be a certain amount of propellant residue left in the chamber and barrel, so perhaps a generous chamber and very deep rifling that that barely engages the driving band (perhaps serrated plastic so no energy is spent deforming the band into the rifling). Perhaps a pressurized cavity in the magazines to hold compressed gas that would flush out the combustion areas after each shot and cool them? Although an exhaust port for the propellant gasses might serve that purpose?

[Jim Watson]

If it is to burn out in the length of the barrel, then the acceleration is the same as a bullet and recoil will be pronounced.

[Trebor]

Make it .45 to .50 caliber, just because many people, rightly or wrongly, prefer a big-bore to a small one. No other reason.

One problem here is that any rocket over a certain size is classified as a "Destructive Device" by the ATF. The original Gyrojet ammo had to be redesigned to a smaller size when the ATF changed the rules and reclassified all the then-existing ammo as DD's.

There are several other technical challenges involved as well. Personally though, I don't see the point. Standard cartridge ammuntion works much better than even an improved Gyrojet would work for any practical application.

Now, if someone had the cash and the ability and wanted to attempt to solve the technical problems just to solve them, for the heck of it, that's another thing entirely. More power to you. Just don't expect to wind up with anything that has any practical self defense purpose.

[Car Knocker]

Just don't expect to wind up with anything that has any practical self defense purpose.

I think the muzzleloader folks said much the same thing about them newfangled breechloaders! :)

Innovation comes through experimentation. Cartridge guns aren't the end of the evolutionary line.

[Jim Watson]

Well, yeah, that "certain size" is .50 caliber which is why the first run of Gyrojets was 13mm and later ones were 12mm.

I always thought the military application for the notion was a machine gun.
You could have a heavy machine gun that weighed 10 pounds and didn't recoil at all. Everybody could hump more ammo. Lack of accuracy and a 25 yard burnout would not be much of a problem for area fire.

[Lo.Com.Denom]

Some good ideas there, Car Knocker! Hadn't thought of a spring-powered chamber insert before.

Do you figure that there'd be more fouling than a conventional round? I think we'll use some fairly regular pistol powder for propellant -- unless there's a reason not to, of course.

Unfortunatly rockets don't work that way

True. But that was a major failing of the original, so we have to eliminate it. Let's call it a "Fixed-case projectile" or something, rather than a rocket.

If it is to burn out in the length of the barrel, then the acceleration is the same as a bullet and recoil will be pronounced.

I figure we'll make the round (minus the weight of the powder and filament) quite light, to cut down on recoil. I haven't thought up any numbers yet, but let's have it going at a fairly high velocity and rely on that and the hardened steel nose to give reasonable penetration. I'm assuming that the recoil would be about the same, if you were to put a really light bullet in a .45 ACP.

Personally though, I don't see the point. Standard cartridge ammuntion works much better than even an improved Gyrojet would work for any practical application.

Hah! I'll tip my hat, when I fly over your cave in my hover-car...:neener:

[MCgunner]

So, maybe you could install a miniature nuclear warhead on the "bullets"?:rolleyes: Oh, oh, I've got it, a heat seeking warhead on it that would track body heat.:D

"Meet George Jetson,
his daughter, Judy;
his boy Elroy,
Jane, his wife....."

[Josh Aston]

Do you figure that there'd be more fouling than a conventional round? I think we'll use some fairly regular pistol powder for propellant -- unless there's a reason not to, of course.

By using regular gun powder you have just eliminated the whole concept. You no longer have a gyrojet, but rather are left with a pistol instead of a handheld rocket launcher.

Caseless and even bulletless ammunition has already been done, in fact it was done well over a hundred years ago with the Volition firearms. At it's current level of development caseless ammunition is certainly workable, but it doesn't work as well as conventional munitions. The bulletless rounds were a rather interesting concept and with a little more development would probably work better than conventional ammunition for handguns at least. But due to it's nature it had to be straightwalled, so I don't think it would ever be able to surpass rifle munitions.

I do find the gyrojet concept rather interesting, but I think it's applications are rather limited. With a laser guidance system it would make an awesome sniper round. Just put the red dot on the target, pull the trigger, and wait until the target drops. It would also work well as a grenade launcher. Think a 203 with no recoil.

[Car Knocker]

LCD,

Propellant residue is dependent upon the type of propellant used. The current gunpowders would be relatively difficult to ignite with a filament and the low pressure would likely result in excessive residue (think low-pressure Unique load).

Remember, though, use of gunpowder will require a container of some sort and a means of removing it from the chamber (you're back to a cartridge). Casting or compressing gunpowder into a self-containing mass won't work as gunpowder depends on the shape of the granules and coatings to control combustion. Gunpowder also would mean that you are just using pressure and not a rocket motor to drive the projectile. The two concepts require very different containment systems. Consider the shoulder-launched RPGs and TOW missiles. They require very light launchers compared to the same size projectiles driven by gunpowder out of a howitzer.

Freeman Dyson at Cal-Tech, several decades ago, pioneered the concept of a spacecraft accelerated by nuclear bombs detonated behind a massive shield at the base of the craft. I believe that he made a small non-nuclear model that he use to successfully demonstrate the principle. Using this principle, it may be possible to accelerate a projectile down a barrel using a series of sequentially-detonated explosives (visualualize ever-stronger primers being detonated as the projectile moves down the barrel). Just thought I would throw this out to widen the scope of brain-storming.

Another concept to consider would be a shaped propellant container that would drop off when the projectile cleared the barrel, much like the shot wad in a shotgun shell or a sabot. The rifling engaging segment could be molded in this portion and would have the advantage of releasing a ballistically clean projectile. The container could be molded with a proper venturi, also.

[Lo.Com.Denom]

Well, the point of this thread was not "how do we build a rocket-pistol?" (I think we're all aware that, sans warhead, you might as well be launching bottle-rockets at someone), it was "how do we make the Gyrojet better?". i.e. Working back, eliminating the things that made Gyrojet so bad. The short answer would be "Throw it in the bin and get yourself a proper gun", but that would be far too dull. Who want's to see in the year 2100 (er, through the windows of our cryogenic emersion tanks...) with a single-stack 1911 on their hips?

So break out the paddles, shout "Clear!" and let's revive this dead horse, people...

The current gunpowders would be relatively difficult to ignite with a filament and the low pressure would likely result in excessive residue (think low-pressure Unique load).


Couldn't we coat the filament in some sort of primer compound? My original thoughts weren't of casting the propellant at all, but rather keeping it loose inside the round, like the old "Volcanic" rounds. But OK, no biggie, we'll just use some different propellant.

You know, the more we go into this, the further I lean towards G11-esque caseless ammo. Seems like having the case leave, attached to the bullet is more trouble than it's worth after all. Also, with my "crimped opening" idea, I'd have to make sure that all those segments opened up uniformly each time, which is another headache. Interesting theory about the sequential ignition. I think I saw some slo-mo footage of that model aircraft once...

I'm sticking with filament-ignition, though. Saves the breach-face from having to have a hole for the firing pin, which, I assume, would be a problem from the obturation point of view.

And yeah, I could have called this "Reserecting The Volcanic", I suppose, but Gyrojet was being discussed on another thread at the time. Seemed more topical, that's all.

[Oldnamvet]

Reading this it almost seems like we'd be turning it into an electronically fired caseless cartridge -- which I think has been done?

[Wes Janson]

Will someone tell me what's wrong with the basic Gyrojet primer ignition system?

[Giolli Joker]

Maybe you'll find this (http://www.deathwind.com/project.htm) interesting.;)