REAL firearms research - explosive casings

[heron]

I think a system should just use projectiles: Load a bullet, inject a combustible mix in a chamber, spark it, repeat process.

This approach then requires some method of getting the bullet to seal tightly in the chamber; the fuel mix can't be allowed to escape past the bullet, and the bullet and chamber have to remain tightly sealed for some time . . . you might get the weapon charged and then have to pause for any number of reasons before firing. If the chamber gets too hot, the fuel might self-ignite; too cold and the fuel might condense in the chamber and fire unevenly. If it can leak at all, you could soon wind up with a squib. To me, that sounds like a really difficult thing to achieve.

You may decide to design the system so that the fuel intake becomes an integral part of the firing cycle (fuel doesn't enter until the trigger is pulled), but then, the fuel intake process becomes a factor in lock time.

 

[mondocomputerman]

"Trying to fix something that isn't broken, especially in the ammunition area, is pretty senseless... and of course, it doesn't work."

I guess we should have stuck to cap and ball. Or muzzleloaders. No need for an enclosed cartrige or any innovation for that matter...

 

[Avenger29]

I guess we should have stuck to cap and ball. Or muzzleloaders. No need for an enclosed cartrige or any innovation for that matter...

Except with muzzleloaders, cap and ball, and blackpowder metallic cartridges, there was lots and lots of reason for improving technology.

With smokeless cartridge arms, reliability is high, efficiency is pretty high, and durability is high. The system is also pretty simple. Talking about injecting air to cool stuff, electronic ignition, etc just makes stuff more complex and prone to failure.

Cartridges as they are today are pretty darn good. It would not make much sense to make a much more complex system just to get rid of brass casings.

 

[LaserSpot]

It sounds like the initial idea was to get rid of the brass case to save weight and cost, thereby allowing more bullets to be sprayed at the enemy. That's not the way we're heading now. Many new weapon systems are designed to reduce collateral damage and increase killing efficiency by take advantage of sensors, electronic intelligence, lasers, GPS, etc...

I think Gyrojet type ammo (it is caseless) is more practical because it solves a lot of problems. No extreme heat and pressure means that the launcher can be very light weight. It would also produce much less noise so you're more likely to hear the enemy and they're less likely to hear you. It would be guided so you don't need hundreds of rounds to ensure a kill.

Metal Storm is also a strong contender. Keep in mind that the army is starting to buy a lot of robots, not just for surveillance and bomb disposal either. Metal Storm type weapons would be maintenance free and ideal for future robots that are designed to sit in the bushes for weeks doing surveillance and ambush. It should work well in unmanned combat air vehicles too.

For close combat and self defense, I don't think fixed metallic ammunition will be replaced.



This is the kind of technology we'll be seeing:

Darpa, the Defense Department’s far-out research arm, announced a pair of contracts last Tuesday, to start designing a super, .50-caliber sniper rifle that fires guided bullets. Lockheed Martin received $12.3 million for the "Exacto," or Extreme Accuracy Tasked Ordnance, project, while Teledyne Scientific & Imaging got another $9.5 million.

http://www.wired.com/dangerroom/2008/11/what-if-a-snipe

This is actually in use! A cluster bomb deploys dozens of tank killing robots. Each robot uses a infrared sensors, lasers and image processors to identify tanks and other vehicles, then destroy them.

The BLU-108 Sensor Fuzed submunition contains four smart Skeet™ warheads equipped with dual-mode passive infrared and active laser sensors for target detection and engagement.

http://www.textrondefense.com/products/airlaunched/blu108.htm
http://www.youtube.com/watch?v=AKdFCsycYm8

 

[Bill_Rights]

LaserSpot,

Great observations and thanks for heads-up on those contract awards. I agree with most of your other points, too.

As for :

A) the initial idea was to get rid of the brass case to save weight and cost, B) thereby allowing more bullets to be sprayed at the enemy.

Your point "A" was exactly spot on. Your conclusion "B" is way off. The Army wants dis-mounted, mobile units to retain the same firepower as now but be able to walk on longer missions or carry more other gear. Less ammo weight trades to more water, food or just less physical exertion. OR trades to more batteries or other mission-specific "payload", if you permit me so to speak. Or some mixture of those two trades.

Or, the same everything else, just more shootable rounds of ammo.

We might be more careful than to say things like

That's not the way we're heading now.

If fact, where we're headed is where the next enemy drags us, if we can't outsmart him and have to rely on raw capability. On top of that, I think you know that within every military Service arm, there are multiple "constituencies". Evidently, the RFP for combustible-cased ammo is from that group within the Army that thinks there will always be a need for multi-soldier "boots on the ground" units walking into a hell-hole, clearing it, holding it, conducting operations from there a while, moving on, doing it again, getting back to base or extracted, etc. and doing it again. Snipers, armor, helicopters and artillary from over the horizon can't do everything, no matter what the capability of their weapons.

The whole point of lighter weight ammo is to get a person or team of humans onto a mission-determined patch of geography on the planet.

(Of course, vehicle and unmanned assets benefit from lighter weight too, but this RFP was clearly from the folks in the Army who think about human units on the ground).

 

[double bogey]

You may decide to design the system so that the fuel intake becomes an integral part of the firing cycle (fuel doesn't enter until the trigger is pulled), but then, the fuel intake process becomes a factor in lock time.

Heron, think diesel engine injector. As the trigger is pulled, fuel air mix is injected and spark happens. Of course I haven't figured out how to get the projectile in place yet, I'm sure there are smarter people than me in the munitions biz. Then there are other things, you wouldn't want to take a hit to your fuel tank in combat.

 

[Blakenzy]

Not so long ago I posted a thread asking why militaries do not use aluminum cases instead of brass, since it is not only a cheaper and currently available technology, but would go a looong way towards solving weight issues for infantry. I don't think anyone had a straight answer.

I think that in the end new cartridge systems are just low priority and not worth the institution's time. R&D, field testing, procurement and full replacement of what is currently in use is just to much trouble to go through and end up with a weapon of exact same practical effectiveness. Sure, it might be nice for the individual grunt to have caseless ammo, but it will not have a huge impact on what a rifle company will or will not be able to do. It is not a game changer. Now when energy weapons become feasible....

 

[heron]

you wouldn't want to take a hit to your fuel tank in combat.

I hadn't thought about the fuel tank, and my first reaction was to think it would be another weight penalty of this system. I got this steam-punk vision of a big can on the soldier's back, like a fire-extinguisher, with a hose leading to the rifle -- and don't forget the carburetor!

Actually that isn't the case -- think of how many rounds you could get out of a can of butane lighter fuel. A few ounces, compared to maybe a couple of pounds of brass-cased ammo, and smaller as well. Give it titanium armor, and yes, hope it doesn't get hit.

 

[Mike OTDP]

Look up H&K G11. The Germans were about to adopt it, but the Berlin Wall came down and they needed the money for reunification.

 

[benEzra]

I hadn't thought about the fuel tank, and my first reaction was to think it would be another weight penalty of this system. I got this steam-punk vision of a big can on the soldier's back, like a fire-extinguisher, with a hose leading to the rifle -- and don't forget the carburetor!

Actually that isn't the case -- think of how many rounds you could get out of a can of butane lighter fuel. A few ounces, compared to maybe a couple of pounds of brass-cased ammo, and smaller as well. Give it titanium armor, and yes, hope it doesn't get hit.

The problem is, you need a tank of fuel AND a tank of oxidizer, AND you can't just inject an appropriate amount in the chamber and light it off like a potato gun. Atomized liquid propellants don't burn slowly enough at 1000+ degrees and 50,000+ psi to smoothly accelerate a projectile, so you need the capability to continuously inject more fuel and propellant into the chamber WHILE the combustion is ongoing and the projectile is accelerating in order to get performance anywhere near that of a conventional firearm.

Now, think of the injection system you need to safely inject fuel AND oxidizer against 50,000 psi backpressure with .9999 reliability. Then think about the power requirements. That's going to be a lot heavier than a few PMAG's and some web gear.

IIRC, the Crusader's prototype system used a gas piston system to do the heavy lifting with regard to the post-ignition injection, which helped with the weight and power requirements, but you then run into the problem of detonation in the propellant staging chamber (where the fuel and oxidizer must both be present to be forced into the firing chamber by the piston), and IIRC such detonation was one of the issues that led the Army to give up on the liquid propellant artillery thing and just go with conventional solid propellants.

 

[Manco]

Heron, think diesel engine injector. As the trigger is pulled, fuel air mix is injected and spark happens. Of course I haven't figured out how to get the projectile in place yet, I'm sure there are smarter people than me in the munitions biz.

In the end, it has to be as simple and effective overall as the current system, and thus far nobody has been able to figure out a better system. Much like evolution, technology growth in any particular field often happens in spurts depending on when there is a critical mass of new knowledge and a sufficient need for new developments. I think the fact that we're in the midst of rapid growth in the electronics and computing fields somehow gives people the expectation that similar growth should be taking place in all fields, but this is simply not the case. I know some people who look at their laptop computers, which are about as powerful as the massive multimillion-dollar supercomputers of 30 years ago, and think that we should be colonizing planets in other star systems by now because of "technology," but we cannot because we neither have the knowledge nor the technology to do so (and may NEVER have it, for all we know right now). We can, however, pretend to on our laptops in 3D video games rendered in real-time.

Firearms have not changed much in the past century, and while I may well be wrong, I don't expect them to change much for perhaps another century, if not longer. Even the Halo series of video games still has humans using the same types of firearms we're using today, and that's because they're pretty close to ideal technologically and they work well.

Then there are other things, you wouldn't want to take a hit to your fuel tank in combat.

That's one reason to avoid liquid propellants. With current weapons, the same thing could happen if your ammo gets hit, but the solid propellants are probably safer in that case since they won't cling to people. By the way, the proposed system could be viewed as an autoloading development of the powder flask or horn, which in the context of personal arms could be considered less sophisticated or "advanced" than self-contained metallic cartridges, which are still state-of-the-art at present with no obvious knowledge or technology to replace them.

 

[-v-]

n the end, it has to be as simple and effective overall as the current system, and thus far nobody has been able to figure out a better system. Much like evolution, technology growth in any particular field often happens in spurts depending on when there is a critical mass of new knowledge and a sufficient need for new developments. I think the fact that we're in the midst of rapid growth in the electronics and computing fields somehow gives people the expectation that similar growth should be taking place in all fields, but this is simply not the case.

Almost. There also has to be a drive to do it. With the electronics industry, there is a vast consumer base with a lot of spare income that wants the newest, fastest, best, and most poweful lap-top so that they can post on Facebook about their new lap top and stream videos and "videos" from the internets at higher and higher resolutions.

In the consumer electronics field there exists now the ideal trifecta of ability, desire, and resources to push that technology through. Same with Medicine right now. Military small arms? Compared to the multi-trillion dollar electronics market, the consumer market for firearms and new technology simply does not exist. We, as gun owners, would rather get a new AR-15 (that is a 60 year old design at this point), then we are to shelf out money on a new, better, but un-tested firearm technology.

Same with major governments. The ability to make caselss ammo is there. The Germans already did it in the late 1980's. What is not there is the desire and consequently the resources (in raw $$$ terms) to make the push to a caseless weapons system.

If no one wants it, no one will shelf out the money to make it, even if it is quite feasible to be made.

 

[LaserSpot]

The whole point of lighter weight ammo is to get a person or team of humans onto a mission-determined patch of geography on the planet.

I'm sure that was the idea, but now they have a new idea. Watch the video, it's really creepy: http://www.wired.com/dangerroom/2008/10/bigdog-20/

The Defense Advanced Research Projects Agency (DARPA) is seeking innovative solutions that will design, build, and test a legged vehicle capable of maneuvering robustly and nimbly among dismounted troops through complex terrain; carrying 400lb of equipment as well as sufficient fuel for 24 hours operation; sensing and negotiating terrain by autonomously selecting appropriate gaits, planning footfalls, and following a soldier through dynamic, cluttered environments; and operating quietly when required.

***

Sure, it might be nice for the individual grunt to have caseless ammo, but it will not have a huge impact on what a rifle company will or will not be able to do. It is not a game changer. Now when energy weapons become feasible....

War is going to become even nastier when we start using megawatt lasers. When used on people, these will be like long-distance flame throwers; instant charred flesh. Even though you may not see the beam, anyone who looks at the guy or the truck getting fried will have seared retinas; permanently blinded. Here's a hundred-kilowatt laser in a C-130 hitting a truck:

Boeing Advanced Tactical Laser In Action: http://www.youtube.com/watch?v=qfmEUqmgsK4

***

Firearms have not changed much in the past century, and while I may well be wrong, I don't expect them to change much for perhaps another century, if not longer.

Probably not, swords haven't changed much in the 800 years since firearms were invented. It took 600 years of product development before firearms were good enough to replace swords. Even then, the military held onto swords for another 100 years.

The answer also depends on how you define "firearm". Is a handheld weapon still a firearm if it fires little guided rockets? Particle beams? Death Rays?

Someday we may have handheld Laser-Induced Plasma Channel weapons that fire lightning bolts; these could replace firearms.

"Laser induced plasma channels (LIPC) combine three of the most awesome things modern science can produce: lasers, plasma, and giant electrical sparks. It's a method of controlling electrical discharges so that they actually hit a specified target, rather than jumping to whatever grounded object happens to be closest."

"The idea behind a laser induced plasma channel is to create a conductive path without the need to provide wires as a physical medium. Instead, powerful ultraviolet lasers can ionize a thin channel of air between the weapon and its target."

http://everything2.com/title/Laser+induced+plasma+channel

 

[benEzra]

Someday we may have handheld Laser-Induced Plasma Channel weapons that fire lightning bolts; these could replace firearms.

If you're a fan of the sci-fi Bolo series books by Keith Laumer and David Weber, the Hellbore (main battery weapon of a Bolo tank) was a laser-induced plasma channel weapon. The concept was that a gigawatt class laser heats the air and ionizes/evacuates the beam path, and then a millisecond later a several-megaton-per-second particle beam is fired down the evacuated path cleared by the laser. Neatly gets around the big disadvantage of particle beam weapons used in an atmosphere, which is atmospheric dispersion/energy dump.

 

[heron]

The problem is, you need a tank of fuel AND a tank of oxidizer, AND you can't just inject an appropriate amount in the chamber and light it off like a potato gun. Atomized liquid propellants don't burn slowly enough at 1000+ degrees and 50,000+ psi to smoothly accelerate a projectile, so you need the capability to continuously inject more fuel and propellant into the chamber WHILE the combustion is ongoing and the projectile is accelerating in order to get performance anywhere near that of a conventional firearm.

There are any number of ways to get a controlled burn; I'm sure that problem can be solved, probably involving the choice of fuel components. Look into some of the things used as rocket fuel for some examples (including rubber hockey pucks!) There are quite a few pairs of chemicals that could serve; some of them react spontaneously without the need of an ignition system. The choices narrow with considerations for safe storage, stability and/or toxicity of the fuel components, and possible toxicity of the reaction's byproducts (it's a no-go if the smoke from the gun barrel can kill you). Note that these reactions might not all be classed as combustion.

Anyone for going back to plain old compressed air? It's been used successfully since at least the Civil War . . .

I have to say, I'm really enjoying this thread; it's one of the most stimulating I've seen in a long time.

 

[LaserSpot]

The problem is, you need a tank of fuel AND a tank of oxidizer, AND you can't just inject an appropriate amount in the chamber and light it off like a potato gun. Atomized liquid propellants don't burn slowly enough at 1000+ degrees and 50,000+ psi to smoothly accelerate a projectile, so you need the capability to continuously inject more fuel and propellant into the chamber WHILE the combustion is ongoing and the projectile is accelerating in order to get performance anywhere near that of a conventional firearm.

At the State Fair, you can fire a BB machine gun. It's basically a hopper full of BBs that feeds into a barrel with compressed air going through it. How about firing a rocket through a Stellite lined barrel that's fed with a hopper full of Buckshot? It sounds like that's the kind of thing you're talking about; might be good for shooting down incoming mortars and RPGs, cheaper to reload than Metal Storm. I'm not sure what the fuel would be; Hydrazine & Nitric acid? I don't think I'd want to strap it on my back!

 

[benEzra]

I'm not sure what the fuel would be; Hydrazine & Nitric acid? I don't think I'd want to strap it on my back!

The Crusader experimental gun used a hydroxylammonium nitrate derivative as the fuel and nitric acid as the oxidizer, I believe. Definitely not something you'd want to carry on your back.

 

[Bill_Rights]

The Big Dog "pack mule" is great: (I actually think doggie boy did quite well on the ice!)

I'm sure that was the idea, but now they have a new idea. Watch the video, it's really creepy: http://www.wired.com/dangerroom/2008/10/bigdog-20/

but it does not replace humans in the situation. Dull and dreary though it was, Gen. Patreus' campaign in Iraq of having foot units "walk, knock and talk" to Iraqi civilians (while camping in barns and one-night-commandeered housing at night) was probably one of the biggest things that turned the situation around in that theater. Big Dog/pack mule is not going to do that and may even be counter productive at the face-to-face meetings. [By the way, there is also an Army RFP out for a replacement engine for Big Dog II - they want to go with "heavy fuel", like UAVs are switching to.]

We got way OT with liquid-propellant small arms, as with "energy weapons" for foot soldiers. That's OK - good to think about. However, that is not what the Army is asking for solutions on today. I think the Army wants combustible-cased ammo that looks, feels and functions exactly like brass-cased ammo. Precisely why is economics - the Army would like to convert the millions of existing small arms to fire the new ammo with nothing more than maybe a bolt change and an alternate but interchangable claw extractor. Ideally, this would be a field-change (or, at worst, an out-post armorer's job), so the same rifle could shoot either combust-case or brass-case, as needed. The requirement before you bid to this RFP is that the ballistics must be >= 10% better with combust-case than with present-day brass-case.

Speaking of economics, Manco and -v- were pretty much correct, except maybe swayed too much by the OT liquid-propellant and "energy weapons" small arms posts. Since the Army limited their request to combustible-cased ammo that is almost interchangable with brass-cased, and certainly uses the same basic long-gun platforms, most of these economic arguments don't directly apply. I think the ammo market for all the small arms in all branches of Service is a big enough market to drive technological innovation. HOWEVER, it is also true that the present Army RFP is somewhat of a "fishing trip", to get people to think about whether, in fact, the technology exists or can be quickly adapted to come up with reasonable combustible-cased ammo. If not, then OK; no contracts will be let against that RFP. And the Army will try again next year or in a few years. No harm, no foul.

 

[Manco]

Almost. There also has to be a drive to do it. With the electronics industry, there is a vast consumer base with a lot of spare income that wants the newest, fastest, best, and most poweful lap-top so that they can post on Facebook about their new lap top and stream videos and "videos" from the internets at higher and higher resolutions.

Well, if I had said "sufficient need and/or desire" then I would have covered it, but the part about knowledge--as in basic scientific and engineering knowledge--still applies. Humanity has enough knowledge of physics to push computers faster and faster for some time to come as long as there is money and impetus for R&D, but for example I doubt that the problems of interstellar travel will be so readily solved without major and unpredictable breakthroughs in our understanding of physics and the universe. As for the advancement of personal firearms, we've had ideas and partial solutions for a very long time now, but there are still some major technological hurdles in the way, mainly related to energy storage and utilization. Such barriers can more easily be overcome in large weapon systems, but personal weapons will remain a challenge for the foreseeable future.

In the consumer electronics field there exists now the ideal trifecta of ability, desire, and resources to push that technology through. Same with Medicine right now. Military small arms? Compared to the multi-trillion dollar electronics market, the consumer market for firearms and new technology simply does not exist. We, as gun owners, would rather get a new AR-15 (that is a 60 year old design at this point), then we are to shelf out money on a new, better, but un-tested firearm technology.

What you say is perfectly valid regarding even minor developments in firearm technology, but I was thinking more in terms of a shift away from explosively-propelled kinetic projectiles altogether.

Same with major governments. The ability to make caselss ammo is there. The Germans already did it in the late 1980's. What is not there is the desire and consequently the resources (in raw $$$ terms) to make the push to a caseless weapons system.

If no one wants it, no one will shelf out the money to make it, even if it is quite feasible to be made.

I'm not convinced that all of the issues had been worked out satisfactorily, and even if there were sufficient R&D drive to bring a workable system to the market (military and civilian), it's still just an incremental improvement over what we have now (I'd place its importance below that of smokeless powder, although we probably could have gotten along without that, too).

Probably not, swords haven't changed much in the 800 years since firearms were invented. It took 600 years of product development before firearms were good enough to replace swords. Even then, the military held onto swords for another 100 years.

The answer also depends on how you define "firearm". Is a handheld weapon still a firearm if it fires little guided rockets? Particle beams? Death Rays?

Personal weapons is what I generally have in mind, although developments in larger weapon systems is also interesting, of course.

Anyone for going back to plain old compressed air? It's been used successfully since at least the Civil War . . .

Is this type of system better overall than firearms? You go first.

 

[LaserSpot]

the Army would like to convert the millions of existing small arms to fire the new ammo with nothing more than maybe a bolt change and an alternate but interchangable claw extractor.

I don't think a bolt could be designed that would seal the chamber well enough and work with an existing barrel. Maybe they should go to a semi-caseless design that uses a metal and plastic head to hold the primer and create the chamber seal.

The Big Dog "pack mule" is great: (I actually think doggie boy did quite well on the ice!)

Sorry to get off topic, but if you saw the Big Dog video (from post 38), this beta version is amusing to watch: http://www.youtube.com/watch?v=VXJZVZFRFJc

 

[Zak Smith]

Justin- that article was a hoot.

 

[stubbicatt]

Isn't the ammo for the Abrams "caseless?" Has a small ring of metal at the breech end with an extractor groove, I think?

 

[Manco]

Isn't the ammo for the Abrams "caseless?" Has a small ring of metal at the breech end with an extractor groove, I think?

It is very close as the rest of the case is consumed, and there are also some examples of electrically-primed ammunition used in cannons. With personal weapons, however, there are usually more drawbacks to these technologies than with large crew-served weapons (e.g. electrical power supply).

 

[Flame Red]

Didn't the big guns on the Iowa Class Battleships use powder bags - case-less ammo??

 

[CapnMac]

Yes, naval rifles are "separate loading" at about the 5-6" bore size.

There were dome variants of naval ammunition that operated like the British 25pdr, in that a case was loaded with powder bags, then loaded behind the round.

The case for this largely involved magazine design, as you can protect bags of powder differently than loaded, assembled rounds. The "gotcha" is time and manpower. If you need to be feeding ready-to-ram loads at 10 or 15 the minute you have a lot of guys below decks stuffing bags into cases. You also have a limit of either having two hoists per breech, or of compromising the case design. The fact that 5" and 6" weapons need to be Dual Purpose (either surface or aerial targets), the AA function needs uniform powder loads to better use ballistic computers for aiming.

Now, at an 8" or larger shell, the breech pressures and powder volumes just make a casing one more complication. Bundling the charges into silk bags (which will 99% combust) is simpler. There is a trick to it though, the rammer energy to seat the round is a great deal higher than for pushing bags of powder. Especially since that last bag has a priming compound base. This last was the final determination of what caused the explosion on Iowa; over-ramming the powder charge.