The Caseless Ammo Weapons Issues and Solutions

[TeufelIV]

More good suggestions. I kind of like that beta vollatic idea. But how much power does that possibly put out? Some systems like laser aiming aides, holo sites, electronic gear, etc are real power hogs.

[VarrusTheEthical]

I'm not sure what the exact output of a Beta Voltaic is, but I've read literature saying that they could power laptop computers. With that as a benchmark, I would assume that they could handle at least lower end power draw of many rifle accessories. The main attraction of a Beta Voltaic for me is that it can power the gun's subsystems for the practical life of the weapon. In other words, you don't need to lug around extra batteries. Just don't breath in the fumes if one of them brakes open.

[Purple]

One thing that strikes me while reading this thread is the sheer complexity of what you people are suggesting. And yes, I know it will be simple from a design perspective but hear me out. What I am getting at is that ideally a soldier should be able to clean and maintain his own weapon in the field with minimal tools and in the shortest amount of time. And once you get to things like batteries, liquid coolant etc. does this still hold true?

[TeufelIV]

Yes. Current weapons systems which require batteries, assorted no powered accessories, and the common parts are maintainable in field to one extent or another just like a bare bones weapon.

[Sea Skimmer]

The only man portable weapons around with anything like liquid coolant are either 100lb machine guns from the first world war, or guided missile launchers which are not even remotely maintainable in the field by the user. If they break, you are shit out of luck. The launcher for Javelin actually has a tiny Sterling engine inside of it to shed heat, but you sure can't handle such a thing like you would a rifle. Laser rangefinders, red dot sights, you sure aren't maintaining those if they break either, but they can be made rugged enough to just not break that often. Anyone designing a rifle or rifle like device which needs active cooling would be a world class idiot.

[VarrusTheEthical]

For keeping the weapon cool, I can think of two things that I have not yet seen suggested.

One is perhaps to simply have a heavy barrel, preferably made out of heat-tolerant alloys, that could act as a heat sink. I'm not what kind of heat capacity you need, but I suspect that it would be enough so long as you're not using the gun as a sustained fire weapon.

Another solution, though I'm not sure if it's practical for a standard issue assault rifle, is to have a quick change barrel. Just like what you see on most modern LMGs. With such a system, I would recommend the barrel have an integrated carrying handle so your soldier does not burn his or her hands changing out the barrels. Perhaps can have a ventilated pouch that your solider could safely store the hot barrel in to cool while you use it's replacement?

And one note on active cooling, though I don't think that would be practical for normal rifle use, if you ever expect to use your gun in space, that may be something to consider. Obviously there would be no air to dump the guns heat into, so you would be restricted to semi-auto firing, if you could fire at alll. If, say, you could attach a bottle of coolant to the rifle to rapidly evacuate heat, the increase in pratical firepower may be worth the extra weight, especially in a low or zero gravity environment.

[TeufelIV]

I don't think a quick change barrel is practical for a infantry rifle.

You can do basic maintenance on gear like cleaning grit and crud and cleaning corrosion off contacts when it happens. Pretty much like your rifle. You perform field maintenance to keep it working and reduce wear and tear. I am not talking about busting them open and replacing components.

[edaw1982]

Why not try Combustible Cased Telescoped ammunition?
Basically a rifle-sized version of this: http://www.army-technology.com/contract ... on/armtec/

[TeufelIV]

If I recall correctly the G11 does use Telescoped ammo and the round is cased in the propellant.

[Batman]

If I recall correctly the G11 does use Telescoped ammo and the round is cased in the propellant.

It would, if it had ever been fielded. It never was, because apparently overcoming the overheating/propellant remnants problem was beyond affordable technology to solve.

[TeufelIV]

The G11 design has not died out. The U.S. military is running a program looking at caseless ammo and the tech the g11 uses is part of the test. The more recent innovation is the new explosive propellant.

[Simon_Jester]

There's a lot of things the army works on to the tune of, oh, a few million dollars a year. Many of them aren't really expected to pay off any time soon, if ever. That's the problem with research and development; you get a lot of ideas that don't pan out, and there's no reliable way to single out the good ones ahead of time.

[Sea Skimmer]

It would, if it had ever been fielded. It never was, because apparently overcoming the overheating/propellant remnants problem was beyond affordable technology to solve.

Some hundreds of G11s were in fact made and issued to German special forces. The gun died because the Cold War ended and it wasn't that great an idea, not because the problems could not be solved. They could be mitigated to an acceptable degree, but it ended up making the weapon and especially the ammunition very expensive and unaffordable in the face of the peace dividend. Overheating could not be avoided for example, but they could put propellent into the ammo with a much higher cook off temperature. Of course, the G11 was also simply using a tiny little bullet, and while the burst ROF was very high, the sustained automatic ROF was very low to reducing the heating rate, which is not good for an all purpose weapon. The same technology in a larger caliber or faster firing rifle likely would have failed given how stressed the G11 design was.

The US is working on caseless ammo again; but it is telling that the same project is pursuing plastic cased ammo at the same pace because they have on confidence that caseless is going to meet all requirements.

[TeufelIV]

On the water cooled Machine guns of WWI. The British Vickers Machine gun only weighed in at just over 50lbs all set up. about 17-20lbs of that is tripod and the rest is the water can if they have one on it. The American Browning Machine Gun was over 100 lbs with ammo, water, and tripod. As with even modern weapon systems the tripod counts for a lot of weight of the weapon system. Add in how these weapons were built and what they were made off they are going to be hefty.

I don't think the differences in rate of fire between sustained auto and burst would have been that big of a problem. Especially considering several modern weapons can go from single shot to burst to full auto without any issues. It might affect the long term wear and tear but that would fall into designing the parts to last longer and normal armoury maintenance of the weapon. Something as carefully designed as the G11 likely already worked out any of those issues. The biggest problem for the whole system was it's total cost. The gun was expensive to make and the ammo was expensive to make.

The original question of the thread got narrowed down to handling the heat that is going to be produced by a caseless ammo weapon system. So far the two best suggestions was something like on the Pecheneg machine gun, M-60E4 and light weight liquid coolant sleeve likely filled with something other then water. I am not sure how the the latest M-60 cooling works though any info would appreciated if any of you know. The issue with the liquid bit is the added logistics and possible weight. I think someone suggested a gas based coolant a page or so back that could be a option as well. Aircooled works reasonably well but even modern weapons break down and parts can be damaged from overheating.

A vid demonstrating a M-4 Carbine fired until it fails.
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It starts to smoke about 3 magazines in. It catches on fire shortly after the 2 minute mark. Well before then the hand guards are going to be hot and difficult to handle. Granted most soldiers are not going to just blow through their ammo like that. It is a good idea to ensure you have some extra room in the design for non-standard conditions.


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And on the other hand we have weapons like the M-60E4


One is an assault rifle the other a machine gun. The trick is to get the assault rifle to be able to take the heat and abuse of a long chain of firing like the M-60E4 does but not make a large heavy weapon.

A from a view point of simplicity and conservation of weight of it is the aircooling option. But which air cooling system to use?

[Batman]

What, exactly, have those got to do with the propellant cooking off issue of caseless ammunition? Those are examples of barrel heating being manageable. Both the M4 and the M60 use ordinary cased ammunition meaning that the issue of overheating of the chambered round has already been greatly reduced thanks to the ejected brass taking most of the waste heat along.

[TeufelIV]

Go read through the rest of of thread. Also the chamber is directly attached to the barrel. When one gets hot it transfers heat to the other via thermal conduction.