As pointed out in a previous post, ammunition has been somewhat stagnant over the last hundred and a bit years. Pretty much every development has been a variation of smaller (or larger) bullets, longer cartridges, fatter cartridges, and more reliable primers and powders. There are a number of restrictions on changing the projectile, so perhaps the launching part of the whole round could be changed.
There are a few advantages of caseless ammunition, which we'll just flick over now:
- Caseless ammunition weighs less and takes up less space, causing less logistical concern for soldiers at the front (it usually translates into weight savings or higher combat endurance for the same weight)
- As caseless ammunition does not need to eject anything, it removes one of the most common causes of weapon jams, resulting in a (probably) more reliable weapon.
Arrayed against these advantages, however, are several less obvious hurdles, some technical and some logistical:
- Starting with the biggest technical issue (that is not already solved to some extent), caseless ammunition generates more heat, and weapons that use them don't have the coincidental heat sinks called cartridges leaving them.
- The vast majority of new designs will require new weapons, rather than much cheaper refits.
- Any changeover would increase logistical strain considerably, especially as two different sorts of small arms ammunition must be transported. This is a tough hurdle as most NATO countries now use the fairly standard 5.56 x 45 mm. The concerns of this particular problem mean that those countries can be considered a single entity as far as ammunition choice.
- There is already existing infrastructure for producing and transporting standard ammunition.
Given all that, it would seem that caseless ammunition has it a bit beat. After all, we're still winning wars (to some extent, anyway), and we're certainly not losing them in such a way that caseless ammunition would change the odds. There is an illusion of a war winning weapon, but wars are rarely won by a single feat of engineering, but a combination of events and a fuckton of diplomacy (and some politics). Common examples would include Muskets, Tanks, the T-34 specifically, the nuclear bomb... Each of those eventually changed warfare to the point where it was almost unrecognisable to the previous generation, but at the outset were usually too premature to have a total strategic effect.
The majority of advances in military technology, one way or another, makes life slightly easier for the grunts who actually have to carry that stuff around. Night vision becomes smaller and more compact, boots more resilient and comfortable, and so on. There is the somewhat facetious argument that says that an ancient suit of armour weighs just as much a modern soldier's kit, and regardless of what flaws that argument has, modern soldiers do carry a lot. Caseless ammunition should be seen as something like that. Every soldier would be relieved of several kilograms (or whatever) of stuff, and anxiety (and death) causing weapon jams would be less frequent.
Given the logistical hurdle of switching over, I think the goal of any nascent caseless ammunition program probably shouldn't be the re-arming of all of NATO. Such goals are extremely ambitious until NATO themselves are more comfortable moving away from a standardised round. However, if a small (but otherwise reasonably wealthy) country picked it up, they would be set. Of course, they would still be extremely lucky should such a thing occur. To do this, they would have to show a demonstration weapon that was at least as field capable as modern assault rifles, and also find a country that wants to separate itself from external or diplomatically uncomfortable logistical chains (and also be really lucky).
Once they had secured a small base of income and a contractual relationship, they should release the patent into the world. One of the bigger weaknesses of the patent system is that governments don't want to contract themselves for twenty years to a sole supplier of some necessary good (though they do often). The original developers of this ammunition would have to treat it more like seatbelts, which Volvo released in the interests of public safety. This would mean that the original developers would be guaranteed less money, but have a head start on both weapons development (which would be necessary) and production.
Those are my thoughts on initial hurdles on the logistics side which are not fully developed. I have a few more thoughts on technical stuff after this.
The hexagonal rifling (no, not the old method of producing guns, this one) method could provide much clearer ability for any residue to leave via the barrel (from the next round fired). It is also overall more effective and durable than regular rifling, which is important for the next little bit. (don't use lead bullets, apparently. Also have a fairly soft gradient from round bullet to polygonal barrel.)
To protect the user against the heat of the barrel, a strong set of grips should be used. However, to stop the gun itself from warping, it would need some other way of containing or bleeding heat that don't negate the benefits of using caseless ammunition in the first place. My suggestion would be to use a principle used in old large buildings like churches; manipulate the airflow that you know exists to bring cool air along. With the advances in computer powered evolved design and 3D printing, I envision almost a web along which heat flows outwards and forces in contact with as much air as possible.
Obviously, we've all seen heat waves rising off the top of a car during summer (if you haven't, apparently being really cold sucks too, I'm sorry). So this, multiplied by the surface area afforded by a circulatory style metal (or whatever transfers heat well), might just allow a weapon to cool itself enough that it won't damage itself with repeated firing. It doesn't have to cool it to be comfortable to touch, just so it doesn't warp.
Hopefully, with that natural anti-heating design and the fact that the bolt for a caseless weapon could be a lot more compact, the entire thing would end up weighing significantly less than a current NATO rifle and ammunition. It may even end up being more effective (seeing as almost all of our current weapons are variations on the same theme) at some stage, allowing standardisation amongst a bloc of nations to be a palatable option.
Obviously, this whole thing is very far off, and would require a risk averse and wealthy company. But I do think the dominoes, so to speak, are quite close.