The Large Magazine Problem.

[Nolo]

In my research on infantry rifle technology and history, it has become clear to me that ammunition, in whatever bullet weight and velocity, will be significantly lighter and smaller in the future.
Since 60 rounds may end up weighing what 30 used to, and since they will take up less space, we have ourselves and opportunity in firearm design, if only we can seize on it.
I need not tell you that, since the beginning of the 20th Century, the box magazine has been king. It is simple to make and clean, reliable and durable. Recently, it has even been proven to be effective when made entirely out of plastic.
Now that we are on the verge of lighter, more compact ammunition, we have the opportunity to make the super-high-capacity magazine a practical method. Previously, these magazines were inherently too heavy and bulky to be practical, even if the reliability and complexity issues could be solved.
Now the inherent drawbacks of this method are about to be mitigated. There is an opportunity here to make some design headway.
How about we start some work on super-high-capacity magazines? It seems like an opportunity that would be silly to miss.

There are a few existing types:
Pan
Drum
Helical
Spiral
Double Drum (saddlebags)
Horizontal-Feed (P90-style)

I'd like to hear some of THR's ideas before I start spouting off my own.
And thanks in advance for all your input, comments and criticism.

 

[chris in va]

We might actually see just projectiles fired by an external power source, not unlike paintball actually.

It's much more efficient to have a bulk 'power pack' and separate, tightly lined up bullets.

 

[Nolo]

We might actually see just projectiles fired by an external power source, not unlike paintball actually.

It's much more efficient to have a bulk 'power pack' and separate, tightly lined up bullets.

I have taken that into consideration as well, but you'd still need a magazine. Would you want to have to reload after 30 or 60, 90, 120 rounds?
Bigger is better, if we can make it better (which I think we can, hence the thread. )

 

[Wes Janson]

I strongly doubt we'll see any significant decreases in the size factor of military rifle ammunition in the forseeable future. We're pretty well pushing the limits of physics as is, and the 5.7x28 is never going to become a standard issue rifle round (nor will anything else of that size) barring complete insanity on the part of the procurement officers.

 

[Ian]

There are some quad-stack box mags out there (Suomi, AK74) that would fit the bill pretty well...

The guns the need the most ammo are already using belts, and I doubt anything would be much more compact than that. New lighter ammo would probably require minimal changes to a belt-fed system.

 

[PercyShelley]

barring complete insanity on the part of the procurement officers.

Given how folks here complain about the 5.56x45mm, the M14, the EM-2, the S-80, The .276 Pederson, et cetera multa, I'm not entirely convinced that the ordinance officials wouldn't do something like that.

 

[Nolo]

Percy, you're aware of the advances I'm considering (plastic-cased, telescoping, shaped fuels and caseless ammo), what is your input on the matter?

 

[poorfolks]

hk has been playing with the idea for years

http://www.remtek.com/arms/hk/mil/g11/caseless.htm

4.7 mm (.185 inch) projectile in a case less cartridge.

 

[PercyShelley]

Seeing as the only people seriously pursuing caseless are the good folks at AAI, and their model is belt-fed, I'm not sure if magazine configuration will come up.

But that's kind of a cop-out answer.

My thought is that a magazine that has no spring, or a weak spring, and feeds by power from the gun's action cycling, like in the old Lewis gun, might be better for caseless ammunition. Since there's no stiff brass case to take all the force, subjecting the ammunition to constant squeezing may not be the best idea.

Methinks that the g11's square ammunition may have been square to help spread out the forces from being in the magazine as much as it was an attempt to improve geometrical efficiency.

I wonder too if HK's old idea about getting rid of the magazine altogether might resurface. HK high-reliability steel STANAG magazines are .75 pounds empty, so you could shave off some weight for more ammunition if you were using some sort of clip. Look up the HK36 (not the G-36). 4.6mm assault rifle with a fixed magazine. Less muzzle velocity than the 5.56 too. Some folks like high velocity, small caliber. Some people like full caliber, moderate velocity. I'm pretty sure that tiny projectile, moderate velocity was only a passing craze.

I would like a caseless rifle with an integral magazine that can be topped off like the johnson rifle or a shotgun, along with a round counter. Would have a very futuristic feel, I think.

 

[Domino]

I personally don't see any advances that will be quite that significant with conventional firearms.

The main problem with caseless ammo is that too much heat is generated because the heat is transferred directly to the chamber instead of an empty case. Also, caseless ammunition is more sensitive to water and humidity and they do not hold together well in large capacity magazines that put lots of pressure on the ammunition. Caseless ammunition is more or less dead right now, I don't see it taking over any time soon.

Polymer-cased ammo on the other hand is a lot lighter than conventional steel or brass cased ammunition. It also generates less heat than metal cases. But, it doesn't make the ammunition smaller and its not reloadable. Even if you can make a magazine that takes a few more rounds than a standard m-16 30 rounder and maintains the same weight; the magazine itself would be even more cumbersome and bulky. I don't see polymer cased ammunition making a push for any ultra high capacity magazines either.

Also, with the latest trend in caliber wars for infantry fighting rifles it seems everyone is going for something larger over the 5.56X45. So if there is any change in caliber in the near future it will probably actually be bigger.

As far as magazines go, reliability and compexity are always problems with high capacity magazines and in the battlefield it is almost always better to keep it as simple as possible. That is why you don't see the average soldier running around with a Beta-C magazine, it just isn't necessary or practical.

 

[PercyShelley]

The main problem with caseless ammo is that too much heat is generated because the heat is transferred directly to the chamber instead of an empty case. Also, caseless ammunition is more sensitive to water and humidity and they do not hold together well in large capacity magazines that put lots of pressure on the ammunition. Caseless ammunition is more or less dead right now, I don't see it taking over any time soon.

AAI is currently working on a squad support weapon with caseless ammunition. The caseless ammunition chemistry is based on the high-ignition-temperature-propellant used in the HK G11.

http://www.dtic.mil/ndia/2007smallarms/5_9_07/Spiegel_820am.pdf

 

[everallm]

OK, basic constraints.

1. Rounds need to be kept in as compact a form package as practical
2. The form package needs to be practical and ergonomic to store, handle and carry on the standard infantry load bearnmg gear
3. Reliability is essential

Now unless we move to a separate liquid propellant system and bullet combo or rail gun format we are restricted to a fairly similar to current cartridge format, possibly polymer case, possibly telescoping, possibly caseless. It's all a small iterative change to the current platform.

So we are likely, in the medium term to stay with a similar form factor as the current STANAG magazine.

Lets look at the magazine, first weight change is to move to lighter, stronger polymer. Next is where else can we save space and weight?

Here we have the spring and follower which can eat up to 15-20% of the magazine capacity.

Quickest fit here is to take an adaptation of the chain gun principle. Rounds are held and fed with a flat lightweight looped chain mechanism at the front and rear of the cartridge. The magazine will be a little larger front to back but will probably increase a 30 round magazine capacity by another 5-10 rounds.

With this type of feed mechanism it would probably be practical to "fold" the magazine so you have a single, double thickness 80 round mag.

 

[Feanaro]

The AAI's cased and caseless ammo designs are featured in August's American Rifleman. I was really intrigued by the article, the concept holds some promise. Their "Serial Number 1" MG has a rotating chamber, which might alleviate the heat transfer issue.

 

[HorseSoldier]

There are some quad-stack box mags out there (Suomi, AK74) that would fit the bill pretty well...

+1 what Ian said.

A lot of the other options mentioned in the original post are workable when on the weapon, but simply suck for the guy with six or them stuck in his load bearing equipment or whatnot.

Same problem, I think, with the existing G11 magazines -- which are single stack mags. You can carry two spares on the gun, but any other look like they'd be ungainly stuck in pouches in webbing.

We might actually see just projectiles fired by an external power source, not unlike paintball actually.

Generation after next, I wouldn't be surprised if we see something like that with chemical propellant or rail gun sort of things. Lot of hurdles to sort out along the way, though.

 

[thebucket]

A linkless drum system like what is used in most fighter aircraft gun systems would allow ammo to be packed as tightly as possible while still allowing smooth operation. Drums now work on springs and belts have links/cloth which increase the amount of space the ammo takes up. The rifle would have to be designed to operate the system using the firing energy but I don't think that would be a serious technical problem as belt fed systems are already powered by the energy of firing. Oddly enough I had been thinking of this earlier today before I even read this post.

I could see a BIG issue with liquid propellants though, the metering system. Ensuring the exact and proper amount of propellant is injected into the chamber everytime could be difficult especially if the chamber is gunked up with soot and residue. Plus the metering system may be subject to physical damage preventing it from metering the proper amount. A chamber with too much or too little propellant could result in a KB. However the system would work, it would be ABSOLUTELY necessary that it work perfectly all the time, in any condition.

 

[mr.trooper]

P90 style magazines already place lots of rounds in a compact package. If you can get smaller munitions with the same level of power, you could have a weapon of the same dimensions with higher capacity.

 

[elmerfudd]

Maybe quad stack mags like the fabled ones for the AK74, but I'm thinking the rifle is pretty close to perfected right now and the next big improvement will be something along the lines of a phased plasma rifle in the 40W range.

 

[Wes Janson]

It's worth pointing out that the military has already spent a considerable amount of money and time testing pretty much every idea mentioned here, and has been doing so continuously for decades. And yet we still have brass-cased percussion-fired ammunition. It's not just that the military is too lazy or unimaginative, it's also the minor fact that most every other option out there has tremendous drawbacks or flaws in it.

 

[Art Eatman]

And there seems to be perception that a larger-diameter bullet would be an improvement over a .22--which means the cartridge itself won't have a smaller diameter. Bottleneck cartridges function more smoothly than straight-wall.

What the "good idea" folks often lose sight of is that that poor grunt has to tote all that stuff. "Externally-fired" means something that's otherwise useless has to be carried/maintained/replaced. So far, brass-cased ammo works better from a logistics standpoint than anything else. Durability for long-term storage as well as mechanical strength for rough handling.