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“Soldiers may soon have a solution . . . that cuts the weight of small-arms ammunition nearly in half and provides a potential replacement for the SAW that weighs a whopping 8.3 pounds less than the current M249,” military.com reports. “The weight reduction comes in the form of a new light machine gun and ammunition developed by engineers from the Lightweight Small Arms Technologies [LSAT] program.” According to Kori Phillips, systems management engineer with Joisey-based ARDEC [Armament Research, Development and Engineering Center], “We are using cased telescoped ammunition which uses a strong plastic case instead of a traditional brass case.” And that means . . .

With a basic load of 1,000 rounds, the LSAT light machine gun and its cased telescoped ammunition is 20.4 pounds lighter than a traditional SAW with the same amount of standard, brass-cased ammunition.

Despite the significantly reduced weight of the LSAT LMG and its ammo, there is no degradation in accuracy or lethality.

“The cased telescoped ammo still provides the same muzzle velocity, range and accuracy as the brass-cased ammo,” Phillips said. “We’re not sacrificing lethality for weight. The plastic case does the same job.”

In addition to significant weight savings, the LSAT is designed to provide other advantages over the current SAW. With a rotating chamber design, the cased telescoped light machine gun improves reliability.

“We’ve avoided the common problem of failure to feed and failure to eject,” Phillips said. “In the current SAW system, that’s one of the places where you primarily have failures and malfunctions.”

The chamber is unique in that the cartridge goes straight through from feed to eject.
“With a regular SAW, or M249, the chamber and barrel is one piece,” Phillips explained.

“But in this new light machine gun, the chamber rotates back and forth. The system works in a cyclical pattern, so there’s no interference.”

Additionally, the rotating-chamber design provides better heat management. Combined with the insulating properties of the plastic ammo cases the LSAT LMG has potential to decrease the possibility of a cook-off or eliminate them altogether.

Another significant feature is the long-stroke, soft-recoil design, which provides a noticeable reduction in felt recoil over the current SAW. This significantly increases control, thus providing the shooter the ability to put more rounds on target and making the weapon much easier to fire from the standing position as a result of decreased muzzle rise.

Moreover, the LSAT LMG has one other unique feature that the current SAW lacks: the ability to switch to a semi-automatic mode. This feature increases the flexibility of the weapon, allows for the precise engagement of point targets, and helps to conserve ammunition in situations where full-automatic fire may not be necessary or desired.

So what’s not to love? Price? Availability? Inability to surmount bureaucracy? Something. In other words, even if this system is the best thing since sliced Taliban, don’t expect to see it on the battlefield for another decade. Or so.

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43 COMMENTS

  1. I wonder if this will trickle down to the civilian market any time soon, it would be nice if cheap plastic cases were avialable in 45 acp, brass is getting expensive, and that is the main limiting factor in my ability to take advantage of available range time.

    • These are basically little shotgun shells. It would be difficult to adapt the ammo to current chamberings and calibers. Although I’m sure it could be done for revolvers, your P220 or 1911 isn’t going to be shooting cased telescoped ammo anytime soon.

  2. it’s not going to lighten their load it will just make them carry more stuff. which will actually make their load heavier because now as they fire each shot they will shed less weight.

    • I read in a book somewhere, I wish I could remember, that the basic loadout of an infantryman, in terms of weight, hasn’t changed much since the Napoleonic Wars. Obviously the stuff being carried has changed, but military people will always load an infantryman with 60-80 lbs of gear, regardless of how “lightweight” the stuff is.

      • The difference is that you used to carry that gear from battle to battle and set it down before the fighting began. Now I carry all that weight all the time. And any weight reduction will find something dumb to take its place.

  3. Back in the 1990’s, there was some prototype range ammunition that came out. The idea was to save costs, save on brass usage, etc.,etc. The State Department of Corrections used .38 Special rounds, and primarily the Smith & Wesson models 64 and 65, 4” barrel revolvers. The ammunition came in a little pack and the rounds had an aluminum base-to encase the primer. After a short bit, the rest of the casing was white plastic, topped off with a lead semi wadcutter bullet. It appeared like a miniature shotgun shell, if you can imagine it. I actually still believe I have a few of these rounds somewhere. Anyway, as soon as the weapon heated up, the cases started sticking in the cylinder. The hotter the weapon got, the harder is was trying to extract them. I do believe had we continued, the plastic cases would have melted. I don’t see how plastic casings, in a much hotter environment-hot chamber, are not going to start melting and fouling the works.

    • I remember those! The stuff I used was actually back in the 1980’s. It was a wadcutter bullet with a rim molded into the base. This would interlock with the plastic cartridge rim. You could actually remove the bullet and snap it back in place with your fingers. I don’t remember any problems with sticking, but we might not have been shooting it fast enough or in hot enough temperature. I sure wish I had kept a few boxes. Probably very collectable now.

    • The science and technology behind plastics have come a long way since then. High-temperature polymers are everwhere. I don’t know exactly how much heat they can withstand, but some polymers do alright in high temps.

    • The polymer they are using has a melting point that is higher than the point of cook-off. In layman’s terms, the ammo would go bang by itself before it could melt. However, the issue of heat is not really the problem; it has been how the ammunition stays together under cyclic loads. The issue is being resolved, and polymer cased ammo is now machinegun rated. Also, because the case stays together after fire, you can reload it much like brass cased ammo.

    • The ammunition is actually very good. The polymer they are using has a melting point that is higher than the point of cook-off. In layman’s terms, the ammo would go bang by itself before it could melt. However, the issue of heat is not really the problem; it has been how the ammunition stays together under cyclic loads. The issue is being resolved, and polymer cased ammo is now machinegun rated. Also, because the case stays together after fire, you can reload it much like brass cased ammo.

  4. Somewhere recently I read an article that claimed 60% of the heat was dissipated by the ejection of the brass. IOW the brass was a heat sink. Without that sink isn’t the barrel going to be hotter faster? Especially in full auto?

    I want to see how they claim to have solved this problem.

    • what’s so bad about the barrel getting hot? cook off: if the casing doesn’t transfer heat then that’s not a problem. accuracy: if you’re shooting full auto you adjust by the impacts or tracers like normal.

      • It depends on how hot is hot. You don’t want the barrel to warp or otherwise melt, I guess. Maybe it’s not an issue.

    • Never thought of the brass as a heat sink, but it makes sense. It absorbs a lot of heat, and is then ejected out!

    • Actually much the opposite. The plastic case will not transfer heat to the barrel. The brass does not remove heat from the barrel. All the heat in the chamber is from combustion. Much of the heat in the barrel is from friction between the round and the lands. And contrary to some of the posts the “plastic” is not going to melt and stick to the chamber. The polymer they are using has a melting point that is higher than the point of cook-off. In layman’s terms, the ammo would go bang by itself before it could melt. However, the issue of heat is not really the problem; it has been how the ammunition stays together under cyclic loads. The issue is being resolved, and polymer cased ammo is now machinegun rated. Also, because the case stays together after fire, you can reload it much like brass cased ammo.

  5. Super-polymers, like ceramics, are very heat resistant. A nonmetallic gun, including the chamber, barrel and even the springs, is more than possible. Since metal detectors would be unable to register an all-nonmetallic gun, the Federal government banned their manufacture in 1988. Reports persist that such guns have been used by the CIA, but we will never know for sure about that. The bottom line is: if nonmetallic guns are a possibility, why aren’t nonmetallic cartridge cases and even nonmetallic bullets? There’s only one reason that I can think of, and that’s cost. Science is easy. Economics is hard.

        • Even if you made a ceramic gun the BULLETS will still be metal! and thus show up on a metal detector….any other ill thought out fantasies you want to try and turn into urban legends that will be used as arguments by the brady bunch?

  6. Problem: New cartridge adds to logistics load of supply to troops.

    Concern: Can it pass the durability test of the original Browning design, i.e., place on auto, lock the trigger on, and how long until it stops firing. (And in this scenario it is permissible to pour water on the barrel.) They ended the Browning test because they got tired of waiting for it to stop.

    • Problem: New cartridge adds to logistics load of supply to troops.

      I think this is exactly the reason why you won’t be seeing the military change up cartridges anytime soon. Whether it be a plastic cased 5.56 or an attempt to go to a different rifle caliber altogether, the logistics of it are complex and expensive. How much 5.56 do you think the DOD just has lying around waiting to be issued? If we went to a new cartridge there would be millions of rounds just sitting around with no place to call home.

    • I do. I bought 1,000 rounds a few years ago. Great in a bolt gun but had ejection issues in my AR. Every so often one of the cases would seperate at the shoulder. The seperation would not be a clean break and the spent case would catch in the ejection port causing a failure. It happened enough that I deemed the ammo unsuitable for semi-autos and relegated it to varmint patrol in the bolt gun.

  7. Update:

    Gun Tests reviewed polymer-cased .223 ammo in their April 2004 issue, comparing it to 55gr and 52gr brass-cased ammo.

    “…the total approximate weight of each loaded round was 173 grains for the Black Hills Hollow Point and 175 grains for the Georgia Arms FMJ jacketed round. But the PCA rounds weighed only 137 grains, slightly more than a 20-percent weight reduction.”

    “In terms of accuracy, both metal-cased ammunitions outpaced the polymer-bodied rounds. What’s more, they shared the same windage setting. The center of the groups shot with the PCA rounds was approximately 3 inches left at 100 yards. ”

    “The PCA Spectrum ammunition was less consistent. Our best effort was a respectable 1.4 inches, but flyers were more common. Most of the groups were right at 2 inches. ”

    “We would guess that one pitfall of polymer-cased ammunition is mastering the crimping process. Then again there probably were some skeptics that thought the cases would blowout or not function at all. But certainly that was not the case.”

    “Gun Tests Recommends
    PCA Spectrum .223 Rem., $5.12/20. Buy It. At 100 yards the polymer-case PCA Spectrum ammunition may not have produced spectacular results, but it did offer lower carrying weight, a low price and provided acceptable performance, in our view. “

  8. On a side note concerning the civilian market — We know ranges manage to make a pretty penny off of the scrap metal they accumulate. It’s not raking in huge piles of cash for those Vegas vacations, but it is something extra on the side. If plastic cases become all the rage, will range fees increase as ranges try and make up what was lost? I’m not advocating for or against anything here, just playing economist.

  9. Personally, I’m kinda bummed that H&K’s caseless ammo for the G-11 never really panned out. I thought that was a brilliant idea.

  10. You all are forgetting one little thing.

    Do you seriously think the environazis are going to let the military leave plastic casings around the battlefield?

  11. Is this a step towards finally fielding the M41A which fires standard 10mm caseless, explosive-tipped, light armor piercing rounds?

    Seriously, I applaud any technical developments that actually led to improvements. I am not a Ludite. But this seems to be an answer looking for a problem. Lighter ammo would allow the average soldier to carry more. But at what costs? Would we need all new weapons? Could it be reversed engineered for current weapons? Is this an ammo that only works with one weapon?

    What about better performing ammo that works with current weapon systems? How about we finally admit that we are trying to kill people with our guns? Hollow points for an AR in mass production?

    • Is this a step towards finally fielding the M41A which fires standard 10mm caseless, explosive-tipped, light armor piercing rounds?

      +1

  12. If they could do this and have the cartridges still function reliably that would be fantastic for combat applications. I’d still prefer brass for recreation applications because I anticipate they will still be better for reloading.

    -D

  13. Going to plastic ammo may be a backdoor way of disarming us. Without the ability to reload, eventually we’ll run out as individual cases split or get too thin at the neck.

  14. 3-D printing will be cheap enough soon that making your own plastic cases will be feasible and very inexpensive.

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