Nolo
Member
Hmmm... I remember that HK seemed to have solved all the problems. The G11 was combat-grade, no? Certainly if I were to try and "adopt" caseless ammo, I wouldn't do it with a conventional rifle.
The Ultimate Combat Round
- Thread starter Nolo
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HKs G11 basically reached the point where it was ready to start undergoing serious field testing. Why developmentally pretty much feature complete, it was in no way a proven or ready for issue weapon.
The main thing that killed the G11, aside from German reunification, was the HKs performance in the ACR tests of the 1980s. The goal was to investigate future rifle concepts and attemp to increase the hit probability of military rifles by 100%.
Entrants in the ACR trials included the Colt ACR using duplex ammunition. Basically a product improved M16
The Stey ACR a novel bullpup with bottom ejection using platic cases and firing flechettes
The HK G11 caseless rifle
The AAI ACR - another flechette rifle built on AAI's (now part of ATK) experience with the SPIW.
Hughes and ARES dropped out before the ACR tests began. My recollection is that the Hughes gun used a variant of their 'chicklet' plastic cased ammunition, which the ARES AIWS was a derivitive of Eugene Stoners promising FARC.
The main thing that killed the G11, aside from German reunification, was the HKs performance in the ACR tests of the 1980s. The goal was to investigate future rifle concepts and attemp to increase the hit probability of military rifles by 100%.
Entrants in the ACR trials included the Colt ACR using duplex ammunition. Basically a product improved M16
The Stey ACR a novel bullpup with bottom ejection using platic cases and firing flechettes
The HK G11 caseless rifle
The AAI ACR - another flechette rifle built on AAI's (now part of ATK) experience with the SPIW.
Hughes and ARES dropped out before the ACR tests began. My recollection is that the Hughes gun used a variant of their 'chicklet' plastic cased ammunition, which the ARES AIWS was a derivitive of Eugene Stoners promising FARC.
Nolo
Member
I see. Couldn't you, however, resurrect and fully develop the G11?
Tony Williams
Member
Yes, it is also known as "differential recoil" or "floating firing" and is common with AA cannon systems. However, it does not reduce the total recoil force (Newton doesn't allow that!). What happens is that the recoil begins as soon as the barrel and action start moving forwards, and continues through the cycle. So the graph of the recoil impulse, instead of showing sharp peaks and troughs with each shot, is much more level, and that makes automatic fire more controllable.
A designer called Robinson produced small arms using this system, during and after WW2 - including a light .50 BMG cal MG which he fired from the shoulder. I don't know why the idea didn't take off for MGs, but as you say the XM307 seems to be the first modern version. For a rifle, the problem is that there is a looong delay before the gun fires after pulling the trigger, during which time the barrel and action is trundling forwards in the receiver and disturbing the aim, so single-shot accuracy would be poor.
Tony Williams
Member
Caseless ammo does indeed have its problems, but it also has some big advantages, so the question is whether the advantages outweigh the problems. In the case of the HK G11 they probably did - but the ACR trials, in setting a target of a doubled hit probability over the M16, were setting a very high hurdle which none of the competing rifles was able to clear.
It'll be interesting to see how the current lightweight MG trials work out. As I've pointed out in THIS article, they are also looking at a "company MG" able to replace 5.56mm and 7.62mm MGs, which suggests a caseless or plastic-cased round intermediate between them - perhaps with a calibre and ballistics similar to the 6.5mm Grendel. That would make a good basis for an assault rifle too...
It'll be interesting to see how the current lightweight MG trials work out. As I've pointed out in THIS article, they are also looking at a "company MG" able to replace 5.56mm and 7.62mm MGs, which suggests a caseless or plastic-cased round intermediate between them - perhaps with a calibre and ballistics similar to the 6.5mm Grendel. That would make a good basis for an assault rifle too...
Nolo
Member
Tony, I'd like to see a point-by-point discussion of the benefits and disadvantages of caseless ammunition, if you have one.
sturmgewehr
Member
Actually, the G11 was no where near ready for prime time. The Germans had field tested it and it had too many problems to be seriously considered as a main line service rifle.
First off, the internals of the G11 were similar in complexity to a Swiss watch.
Could you imagine getting that thing wet or, God forbid, muddy? Yeah, that won't last long in a war zone. A military rifle must be simple, easily maintained and reliable. The G11 was none of none of the above. It was a great concept, but it had other serious issues...
...like the ammo. It was easily damaged, prone to "cooking off" and the technology just wasn't evolved. It was susceptible to water, the powder would become brittle when stored and ultimately the various prototypes had issues with burning way too dirty (due to the protective coating around the powder).
Here are some of the various ammo prototypes:
Most countries have abandon, at least for now, the caseless concept due to the issues mostly related to the propellant.
First off, the internals of the G11 were similar in complexity to a Swiss watch.
Could you imagine getting that thing wet or, God forbid, muddy? Yeah, that won't last long in a war zone. A military rifle must be simple, easily maintained and reliable. The G11 was none of none of the above. It was a great concept, but it had other serious issues...
...like the ammo. It was easily damaged, prone to "cooking off" and the technology just wasn't evolved. It was susceptible to water, the powder would become brittle when stored and ultimately the various prototypes had issues with burning way too dirty (due to the protective coating around the powder).
Here are some of the various ammo prototypes:
Most countries have abandon, at least for now, the caseless concept due to the issues mostly related to the propellant.
Nolo
Member
The HK's internals, at least in theory, would be completely shut off from any damage, due to the sealed weapon (no ejection port).
Also, the ammunition you have shown there was prone to cook-offs, which is why they switched to the other HTIP propellant (which you can actually see in the picture of the field-stripped G11).
And, yes, the internal mechanism was complex, but I think you could simplify it significantly if you redesigned the weapon. I also heard reports that the G11 was quite reliable in HK's famous mudbath tests. But whether those reports were founded or not, I don't know. As for the dirty and "half-lived" cartridges, I've never heard any reports to support that, but on the gripping hand I've never heard any reports to counter it, either.
Also, the ammunition you have shown there was prone to cook-offs, which is why they switched to the other HTIP propellant (which you can actually see in the picture of the field-stripped G11).
And, yes, the internal mechanism was complex, but I think you could simplify it significantly if you redesigned the weapon. I also heard reports that the G11 was quite reliable in HK's famous mudbath tests. But whether those reports were founded or not, I don't know. As for the dirty and "half-lived" cartridges, I've never heard any reports to support that, but on the gripping hand I've never heard any reports to counter it, either.
Owen
Moderator Emeritus
NOLO
do you think maybe that peoplethe with doctorates that design cartridges maybe have a handle on the efficiency curve and are riding it with their designs?
You're trying to stuff 10 pounds of crap into a 5 pound bag, and wondering why you have poo on your hands.
do you think maybe that peoplethe with doctorates that design cartridges maybe have a handle on the efficiency curve and are riding it with their designs?
You're trying to stuff 10 pounds of crap into a 5 pound bag, and wondering why you have poo on your hands.
sturmgewehr
Member
That's what they thought originally, until they had a bad round and it couldn't be ejected to clear the weapon without field stripping. It would also make unloading the weapon troublesome as well... so, an ejection port is in fact required.
Nolo
Member
I do not understand what you mean, sir.
If you are saying to me "stay away from our area of expertise, we know better, f00l", then all I have to reply to that is:
Kalashnikov as a young boy liked taking things apart, and he liked experimenting.
Eugene Stoner was an inventor from a young age.
You started doing designs before you got your doctorate, I'm sure.
If you think I'm wrong, correct me, don't deride me.
If you are saying to me "stay away from our area of expertise, we know better, f00l", then all I have to reply to that is:
Kalashnikov as a young boy liked taking things apart, and he liked experimenting.
Eugene Stoner was an inventor from a young age.
You started doing designs before you got your doctorate, I'm sure.
If you think I'm wrong, correct me, don't deride me.
Nolo
Member
Touche, Sturmgewer. It was on the underside of the weapon, no?
I wonder if they did the mudbath tests on the prototype with the ejection port.
See, we need more data!
We don't have it.
Ressurect and redesign G11!
I wonder if they did the mudbath tests on the prototype with the ejection port.
See, we need more data!
We don't have it.
Ressurect and redesign G11!
sturmgewehr
Member
This round:
Is the HITP round.
Is the HITP round.
sturmgewehr
Member
I wish the project would have continued, it was promising... and those who fired the G11 were amazed at how easy it was to hit targets out to 300m with multiple rounds (it fired 3 rounds so fast it almost sounded like one shot).
Let's harass HK into bringing it back.
Let's harass HK into bringing it back.
Nolo
Member
Yes, let's.
And that is the early HITP round, the final rounds did not have a protruding bullet:
The final variant is the one on the right.
And that is the early HITP round, the final rounds did not have a protruding bullet:
The final variant is the one on the right.
sturmgewehr
Member
Yeah, I couldn't find a pic of the later round. Obviously they pushed the bullet back in the case to help protect it from damage.
The design was really unique as it had a booster charge just behind the bullet that ignited and pushed the bullet forward, before the rest of the propellant ignited so that it could actually push the round down the barrel vs. just burning around it... it was something of a two stage design, totally unique. I've heard that it too had its share of reliability problems.
The design was really unique as it had a booster charge just behind the bullet that ignited and pushed the bullet forward, before the rest of the propellant ignited so that it could actually push the round down the barrel vs. just burning around it... it was something of a two stage design, totally unique. I've heard that it too had its share of reliability problems.
Nolo
Member
Something like that.
And, strangely, I too couldn't really find a good picture of it either, though I've seen one before.
Yeah that was an interesting design.
If you took the trouble to work on the G11 some more, you'd end up with a truly revolutionary weapon.
I'd put it in 5.5mm, though.
And, strangely, I too couldn't really find a good picture of it either, though I've seen one before.
Yeah that was an interesting design.
If you took the trouble to work on the G11 some more, you'd end up with a truly revolutionary weapon.
I'd put it in 5.5mm, though.
Owen
Moderator Emeritus
I don't have a doctorate, but there are a lot of people in the ballistics field that do.
It's just that you seem surprised that you can't escape the curve generated by existing cartridges. Considering the 130 years plus of development, you're trying to make a radical improvement on an existing, mature technology. In all likelihood, with existing propellents, we are within a few percent of the peak performance for cartridge firearms.
The advances aren't going to come from drawing a new cartridge shape in MS paint. That's already been done. You know that Quickoad program the GunTech is using? The cartridge designers have been using stuff like that for decades. The differnce is that they try hundred of variables at once, generate curves and pick the sweet spots. To the point where they say "I want this ME with this bullet in this length, with the minimum amount of propellant, so me what we can do"
The advances in conventional firearms are going to come from finding better propellants, better materials and ergonomics. Otherwise we are just rearranging deck chairs. 2 of those things are only going to come from a laboratory. TANSTAFL
The G11 is certainly a viable path, but i think you will find that designing on a napkin is a walk in the park compared to building the hardware.
The G11 bankrupted HK, and put a serious dent in Dynamit-Nobel.
(BTW easy on the ashingbay of onyTay illiamsWay He knows what he's talking about. Recoil is all about impulse, and a muzzle brake creates a counter impulse)
It's just that you seem surprised that you can't escape the curve generated by existing cartridges. Considering the 130 years plus of development, you're trying to make a radical improvement on an existing, mature technology. In all likelihood, with existing propellents, we are within a few percent of the peak performance for cartridge firearms.
The advances aren't going to come from drawing a new cartridge shape in MS paint. That's already been done. You know that Quickoad program the GunTech is using? The cartridge designers have been using stuff like that for decades. The differnce is that they try hundred of variables at once, generate curves and pick the sweet spots. To the point where they say "I want this ME with this bullet in this length, with the minimum amount of propellant, so me what we can do"
The advances in conventional firearms are going to come from finding better propellants, better materials and ergonomics. Otherwise we are just rearranging deck chairs. 2 of those things are only going to come from a laboratory. TANSTAFL
The G11 is certainly a viable path, but i think you will find that designing on a napkin is a walk in the park compared to building the hardware.
The G11 bankrupted HK, and put a serious dent in Dynamit-Nobel.
(BTW easy on the ashingbay of onyTay illiamsWay He knows what he's talking about. Recoil is all about impulse, and a muzzle brake creates a counter impulse)
Nolo
Member
I didn't bash him.
I merely disagreed, then realized I was wrong.
I'm allowed to be wrong, no?
The whole thread was designed for me to learn from you, not the other way around. And I did. Most of what I learned was exactly what you said ('cept the napkin stuff, I already knew that, hence the thread). It looked like I had a way out, but it turned out to be a dead end. Which is why I'm now looking at caseless ammo. And it's TANSTAAFL, buddy. Two "A's" in the last part. I don't have the ability to even run data through a computer, much less experiment with cartridges in the real world. I discounted caseless ammo and other things because they weren't perfected and no amount of talk on an internet forum will change that (that's still true). However, bringing cartridge data onto the forum with know and tried and true technologies will get us somewhere. If only half a step forward, it's still progress. And the G11 only bankrupted HK because they put a Hell of alot of time and effort and money into it and did get any reward. That'd bankrupt anybody.
The point is, I think I have something to contribute to you, but I think you have far more to contribute to me.
I merely disagreed, then realized I was wrong.
I'm allowed to be wrong, no?
The whole thread was designed for me to learn from you, not the other way around. And I did. Most of what I learned was exactly what you said ('cept the napkin stuff, I already knew that, hence the thread). It looked like I had a way out, but it turned out to be a dead end. Which is why I'm now looking at caseless ammo. And it's TANSTAAFL, buddy. Two "A's" in the last part. I don't have the ability to even run data through a computer, much less experiment with cartridges in the real world. I discounted caseless ammo and other things because they weren't perfected and no amount of talk on an internet forum will change that (that's still true). However, bringing cartridge data onto the forum with know and tried and true technologies will get us somewhere. If only half a step forward, it's still progress. And the G11 only bankrupted HK because they put a Hell of alot of time and effort and money into it and did get any reward. That'd bankrupt anybody.
The point is, I think I have something to contribute to you, but I think you have far more to contribute to me.
Owen
Moderator Emeritus
you can get the ability to run data pretty easily. The program GunTech is using is called quickload/Quickdesign
http://www.neconos.com/details3.htm
It looks like it'll cost about $300 for the package, which is cheap if you're serious about this.
I haven't played with it much, because I mostly use handguns, and care alot more about shooting than ammunition. Once I find a load that works the gun, and hits the target reliably, I stop development, and crank out 10 or 20k rounds. When I was working as a designer, the ammuntion was a constant, so I didn't really play with it then, either.
http://www.neconos.com/details3a.htm
Buy a physics text book, and a drafting/detailing book. Mechanical design is something you can do on your own. You might want to dig up a copy of Cartridges of the World.
http://www.neconos.com/details3.htm
It looks like it'll cost about $300 for the package, which is cheap if you're serious about this.
I haven't played with it much, because I mostly use handguns, and care alot more about shooting than ammunition. Once I find a load that works the gun, and hits the target reliably, I stop development, and crank out 10 or 20k rounds. When I was working as a designer, the ammuntion was a constant, so I didn't really play with it then, either.
http://www.neconos.com/details3a.htm
Buy a physics text book, and a drafting/detailing book. Mechanical design is something you can do on your own. You might want to dig up a copy of Cartridges of the World.
Tony Williams
Member
A quick summary of pros and cons of caseless ammo, with the HK G11 specifically in mind.
Pros:
1. Ammo weight about half that of a brass round - especially important for MGs, but useful for any poor grunt carrying a huge load (as they do).
2. The action stays shut as it operates - it doesn't open to let in dirt which might jam the mechanism (G11 does have an ejection port, but it's only opened to clear the chamber after firing, or if there's a faulty round).
3. There isn't a case to eject - faulty ejection is a significant contributor to jams.
Cons:
1. Ammo is fragile (G11 met this by providing it in sealed magazine packs)
2. Risk of cook-offs due to lack of brass cases, which remove heat from chamber (Dynamit Nobel pretty well cracked this with insensitive propellant).
3. No brass case to seal the chamber (seems to have been sorted in G11 - it just makes the breech design more difficult).
Clearly, the US was sufficiently impressed by the G11's ammo technology to buy the rights to use it from Dynamit Nobel. It is now being developed for the LSAT MG.
Pros:
1. Ammo weight about half that of a brass round - especially important for MGs, but useful for any poor grunt carrying a huge load (as they do).
2. The action stays shut as it operates - it doesn't open to let in dirt which might jam the mechanism (G11 does have an ejection port, but it's only opened to clear the chamber after firing, or if there's a faulty round).
3. There isn't a case to eject - faulty ejection is a significant contributor to jams.
Cons:
1. Ammo is fragile (G11 met this by providing it in sealed magazine packs)
2. Risk of cook-offs due to lack of brass cases, which remove heat from chamber (Dynamit Nobel pretty well cracked this with insensitive propellant).
3. No brass case to seal the chamber (seems to have been sorted in G11 - it just makes the breech design more difficult).
Clearly, the US was sufficiently impressed by the G11's ammo technology to buy the rights to use it from Dynamit Nobel. It is now being developed for the LSAT MG.
Nolo
Member
Yeah.
Sounds good, with the caseless stuff. Nothing that can't be overcome with development.
Oh, Owen, I don't have $300. I just don't... yet. I'm already on track to become a ME, so that's not an issue, it's what I was going to do anyway.
Sounds good, with the caseless stuff. Nothing that can't be overcome with development.
Oh, Owen, I don't have $300. I just don't... yet. I'm already on track to become a ME, so that's not an issue, it's what I was going to do anyway.
PercyShelley
Member
- Joined
- Feb 15, 2007
- Messages
- 1,075
There are those of us who are of the opinion that, since muskets lacked metallic cartridges, caseless ammunition clearly represents a step backwards.
Actually, if a semi-auto caseless rifle is ever made in the US, I will be first in line to buy the thing, as a salute to brave engineers as much as to the great interest I have in the concept itself. Besides, my AR needs company, and I refuse to house it with one of those poorly bred mongrel AKs!
There is another, less discussed method of improving firearms efficiency I've been peddling about in my head.
Consider the following:
http://www.z-hat.com/Efficiency of the 300 Hawk.htm
About a third of the energy contained in a cartridge becomes waste heat; absorbed by the barrel, action and casing. This heat both fails to propel the bullet any faster and impairs the proper function of the firearm.
If the barrel of a firearm could be lined with a sufficiently hard and insulative substance (ceraplate has been recommended), not only could the barrel be made thinner and lighter, because it would no longer have to function as much as a heat sink, but velocities would improve.
I pitched this idea to Chris Byrne at the Anarchangel blog, and he says that it will cause a lumpy pressure curve that would destroy accuracy (as I understood his words). I'm not so sure; I would think that it would produce a pressure curve that drops off less dramatically towards the end, which would just increase velocity. It is worth noting that Chris Byrne is a trained engineer, and I am not.
Liquid propellants were mentioned earlier, esp. hydrazine, which is one of the nastiest chemicals that man regularly puts in his machines (it's used in the shuttle and F-16 APUs, as well as many satellites). HAN-based monopropellants are much less toxic, and have a higher specific impulse, which should net you some gain in velocity when used as a gun propellant.
Actually, if a semi-auto caseless rifle is ever made in the US, I will be first in line to buy the thing, as a salute to brave engineers as much as to the great interest I have in the concept itself. Besides, my AR needs company, and I refuse to house it with one of those poorly bred mongrel AKs!
There is another, less discussed method of improving firearms efficiency I've been peddling about in my head.
Consider the following:
http://www.z-hat.com/Efficiency of the 300 Hawk.htm
About a third of the energy contained in a cartridge becomes waste heat; absorbed by the barrel, action and casing. This heat both fails to propel the bullet any faster and impairs the proper function of the firearm.
If the barrel of a firearm could be lined with a sufficiently hard and insulative substance (ceraplate has been recommended), not only could the barrel be made thinner and lighter, because it would no longer have to function as much as a heat sink, but velocities would improve.
I pitched this idea to Chris Byrne at the Anarchangel blog, and he says that it will cause a lumpy pressure curve that would destroy accuracy (as I understood his words). I'm not so sure; I would think that it would produce a pressure curve that drops off less dramatically towards the end, which would just increase velocity. It is worth noting that Chris Byrne is a trained engineer, and I am not.
Liquid propellants were mentioned earlier, esp. hydrazine, which is one of the nastiest chemicals that man regularly puts in his machines (it's used in the shuttle and F-16 APUs, as well as many satellites). HAN-based monopropellants are much less toxic, and have a higher specific impulse, which should net you some gain in velocity when used as a gun propellant.
BTW, just because we are gtting into exotica, another solution to the weight/capacuty/energy issue of cartridges is to use a technology like CAP/ET/ETC.
The limiting factor in conventional cartridges pressure is the aability of the chamber to handle peak pressure. Unfortunately, conventional propellants have a sharp pressure spike, while the pressure profile of the barrel is much broader at peak pressure.
If you replace propellant gases with a plasma stimulated working fluid, you can control the pressure curve to match the characteristics of the barrel. The net result is that you can have huge increases in velocity without an increase in case size or peak chamber pressure. The the 1980s Hughes demonstrated a modified M16 that used ET (electro-thermal) to almost double the velocity at the same peak pressure. The the main issue with ET and ETC (Electrothermal chemical) rounds is the demand for externl electrical power. With a whole new generation of supercapacitors on the horizon, ET and ETC guns could become viable very soon.
As Tony noted, there are compelling military reasons for caseless ammo and the weapons that use it. Anyone who has lugges around a lot of ammo and other military impedimenta will immediately recognized the appeal in a reduction of size and weight. The problem is that the military environment is incredibly unforgiving.
There's little civilian appeal for caseless ammo, as there is typically a demand for a large variet of loadings in any given caliber and no ability to 'reload'. Caselss ammo makes most sense when you are manufacturing huge quantities to exactly the same thing. The material making up caseless ammo also tend to be more expensive than standard propellands, offsetting any cost savings.
Finally, my recollection is that HK had issues with their ammo and creating a tracer round. And a lot of traditionally minded infantry types were really keen on going to a bullet that was even smaller than the 5.56x54.
As an aside, there have been at least two civilian firearms that used caseless ammo, and neither was a success. Google 'Daisy VL' and 'Voere VEC 91'
The limiting factor in conventional cartridges pressure is the aability of the chamber to handle peak pressure. Unfortunately, conventional propellants have a sharp pressure spike, while the pressure profile of the barrel is much broader at peak pressure.
If you replace propellant gases with a plasma stimulated working fluid, you can control the pressure curve to match the characteristics of the barrel. The net result is that you can have huge increases in velocity without an increase in case size or peak chamber pressure. The the 1980s Hughes demonstrated a modified M16 that used ET (electro-thermal) to almost double the velocity at the same peak pressure. The the main issue with ET and ETC (Electrothermal chemical) rounds is the demand for externl electrical power. With a whole new generation of supercapacitors on the horizon, ET and ETC guns could become viable very soon.
As Tony noted, there are compelling military reasons for caseless ammo and the weapons that use it. Anyone who has lugges around a lot of ammo and other military impedimenta will immediately recognized the appeal in a reduction of size and weight. The problem is that the military environment is incredibly unforgiving.
There's little civilian appeal for caseless ammo, as there is typically a demand for a large variet of loadings in any given caliber and no ability to 'reload'. Caselss ammo makes most sense when you are manufacturing huge quantities to exactly the same thing. The material making up caseless ammo also tend to be more expensive than standard propellands, offsetting any cost savings.
Finally, my recollection is that HK had issues with their ammo and creating a tracer round. And a lot of traditionally minded infantry types were really keen on going to a bullet that was even smaller than the 5.56x54.
As an aside, there have been at least two civilian firearms that used caseless ammo, and neither was a success. Google 'Daisy VL' and 'Voere VEC 91'
PercyShelley
Member
- Joined
- Feb 15, 2007
- Messages
- 1,075
Electrothermal propulsion is interesting, but current batteries don't have anything like the energy density of chemical propellants. I don't think you could shave enough weight off the barrel to make up for the massive power cells you would have to haul around.
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