American Rifleman has a long history of showcasing the latest developments in military arms and ammunition. What follows is a close look at cutting-edge work that is well underway toward the goal of sharply reducing the infantry soldier’s combat load. It could be the future of U.S. infantry weapons.

By Robert Bruce

   The Lightweight Small Arms Technologies program (LSAT) has been on our radar screen since its inception in 2003. Plastic-cased cartridges are already performing well, and caseless ammunition—a concept dating back to the dawn of firearms—is said to offer the greatest potential. Today, these high-tech cartridges and the innovative lightweight small arms that fire them are showing great promise. What emerges from these experiments is likely to yield benefits not only to the military, but also to law enforcement and to the shooting sports.
   It’s real and right now: a dramatically different squad automatic weapon (SAW) that fires radically new ammunition. And this combination is half the combat weight of the M249, the current SAW. We asked the Army’s program manager how soon it could be in the hands of Americas warfighters? That is a tough question, so lets go back a few years.
   The Army-led Joint Services Small Arms Program (JSSAP) challenged the defense industry to develop and present innovative ideas for dramatically reducing the combined gun and ammunition weight in a family of small arms. These new arms are intended to bridge the gap between what is in use now and the directed energy “ray guns” or other radical armament that might be available to the American soldier of 2025.
   In March 2005 it was publicly announced that the concept from well-respected defense contractor AAI—heading up a team of eight specialized companies—had been judged superior to that of rival General Dynamics, and was “downselected” by JSSAP for further development. At the time, AAI’s proposed Squad Automatic Weapon and its radical ammunition existed only in “virtual reality”—animated 3-D models generated by astonishingly complex computer programs. With JSSAP’s approval and selection of these digital designs came sufficient funding to begin fabrication of actual cartridges and the guns to send rounds downrange.

The Cased Telescoped (CT) ammunition (above) is one of the approaches to meeting LSAT’s weight reduction goals. The most current generation, “Spiral 2” CT, uses specialized polymer formulations for the cartridge case and end cap, but priming is conventional. Six-hundred rounds of 5.56 CT weighs 35 percent less than an equal number of 5.56x45 mm rounds.

Live Fire Demonstration
   By May 2007, things were moving along so well with the Cased Telescoped (CT) ammunition and prototype SAW that Kori Spiegel, JSSAP’s LSAT project manager, took the calculated risk of authorizing the first public LSAT live-fire demonstration held in conjunction with the National Defense Industrial Association’s annual Small Arms Symposium.
   Tim Livelsberger pumped out nearly 50 rounds of CT in flawless semi- and full-automatic operation from the serial number 1 (SN1) light machine gun. This clearly showed that its theoretical potential had been turned into something very real. It seemed that the uncannily light gun and its distinctive plastic “lipstick tube” ammunition were on the fast track to fielding.

Invitation To AAI
   Further inquiries were rewarded with an invitation for the author to visit AAI’s Hunt Valley, Md., headquarters for an exclusive LSAT status briefing in December 2007. This also included the opportunity to formally interview Spiegel and the program’s other top official, AAI’s Paul Shipley, who heads the corporation’s team of industry partners.
   I was brought up to date on the series of successful demonstrations for senior officers and others in the military community that followed LSAT’s public debut seven months earlier. All have included the opportunity to handle and shoot the CT serial number 1 prototype with “Spiral 2” (second generation) cased telescoped ammunition on military ranges with pop-up targets positioned from 100 to 800 meters.
   These demonstrations allow decision makers to assess the system’s combat potential. “Results have been very positive,” Spiegel said, “particularly in favorable comments on the design’s light weight, mild recoil and accuracy—all measurably superior to the current squad automatic weapon.” Live fire video clips of this arm in action are available for viewing at www.americanrifleman.org.
   Shipley told us that the test and demonstration prototype CT SN1 has received a pretty good workout along the way. “We’ve fired about 5,000 rounds in that weapon,” he said, “in temperature conditions from very cold to very hot.”
   So, what’s next? LSAT fact sheets predict the gun and ammunition being transitioned to Program Manager Soldier Weapons (PMSW) in 2010. Why two more years? Spiegel replied this date was a guideline and there are compelling reasons to keep it in “Technology Base” for a bit longer. “It’s more about the best solution,” she explained. “Cased Telescoped [ammunition] is out in front, time-wise—probably between six months to a year ahead of where we are with caseless. We could transition that package tomorrow and PMSW could continue to develop it and then field it in a few years. But we think there’s more potential there and we should work more on the caseless, or in developing other types of weapons, and really find the right fit for our user before … transition.”
   Indeed, as I saw a bit later that day in a visit to AAI’s subterranean small-arms test range, engineers from ARES, the weapon design partner, were working with counterparts from AAI in conducting live-fire experiments with the updated CT SN2 weapon. I received a close look at ATK’s latest caseless ammunition, but the test fixture that fires it—said to be significantly different in mechanical function from that of CT—was literally under wraps for security purposes.
   I asked about “thermal management,” the vexing problem of keeping the LSAT from prematurely overheating. Shipley corrected the misconception that this is particularly challenging in both CT and CL because there is no brass case that ejects along with most of the heat generated on firing. Brass transfers a lot of heat to the chamber, he said, but the CT’s polymer case is an insulator.
   The CT’s “combination of a separate chamber and polymer case results in considerable heat isolation,” Shipley explained. “You can fire to the point where the barrel is too hot to touch yet the chamber is only slightly warm.” And Spiegel said that the high-temperature steel used in the barrel was nothing unusual.
   “There’s no ‘unobtanium’ [miraculous metal] in the weapon itself,” she said. “The only thing we haven’t made a determination on yet is the chamber for the caseless weapon,” she offered. “We are looking at everything including ceramics, approaching it from all angles. We want to find the optimum combination and that will probably be some kind of ‘sandwich,’ but we don’t know yet.”

The Caseless Telescoped (CL) cartridges (top), developed by Alliant TechSystems, use the propellant itself for the role of the “case,” which is fully consumed on firing.

Optimum Caliber
   Proponents of various alternative calibers should take heart. Both Spiegel and Shipley were careful to point out that the conventional G.I. 5.56x45 mm ball and tracer bullets used in the program’s experimental CT ammo serve primarily as a baseline standard since everyone can relate to their performance.
   “There is some other work in the Army for what they’re calling a ‘green bullet’ program which is not only lead-free, but probably has other improvements in it,” Spiegel said. “We’d like to see if we could integrate that with our ammunition as well as look at calibers other than 5.56 millimeter. We would like an optimum caliber, we just don’t know yet what that is.”

Virtual Guns And Ammunition
   LSAT information papers indicate that a lot of the most challenging obstacles in ammunition and firing mechanisms had been cleared ahead of time in super-smart computer models. Both Spiegel and Shipley were quick to credit partner firms for their expertise in this cutting-edge computer science. “They’re bringing gun design into the 21st Century,” Spiegel said. “We did some of it with the Objective Crew Served Weapon (circa 1995) but really the tools weren’t there to do it back then.”
   Once a decision is made on CT vs. CL with a well-developed prototype weapon, the team would like to move the system into limited production stage before handing it off to PMSW. “Our plan is to bring a weapon producer on before that so we can get a little bit of the manufacturing experience,” Spiegel said. “We have a lot of R&D experience on this team, we don’t have a lot of weapon manufacturing experience. We’d like to get a little bit of feedback as far as designing parts, making parts, materials, that kind of thing.”

The Lightweight Small Arms Technologies (LSAT) project is part of the Joint Services Small Arms Program’s search for lighter and better arms.

LSAT’s Future
   JSSAP’s winning LSAT team is uniquely structured to make the best use of the program’s many and very different scientific, technical and soldier-interface disciplines. The lead contractor is defense giant Textron’s AAI subsidiary, with more than a half-century of experience in armament and ammunition development. Its five main partners include ARES for weapon engineering, ATK and General Dynamics’ St. Marks Powder for ammunition, Battelle for material investigation and Omega Training for human factors.
   Cased Telescoped LMG Weapon Prototype serial number 2 is nearing finalization, making best use of important lessons learned along the way and optimized for the latest CT cartridges. A prototype Caseless Telescoped weapon is coming soon.
   At this point, I’ve seen enough evidence on LSAT to convince me that the program is making meaningful progress. This leads to intriguing possibilities for some likely spin-offs and their benefits to military, law enforcement and shooting sports. Consider the deceptively modest phrase “family of weapons” in LSAT fact sheets. Might this family include pistols, rifles and machine guns?
   I learned that AAI is already at work on a lightweight assault rifle to fire the same CT and CL ammunition for the LSAT SAW. This initiative is particularly timely given growing dissatisfaction with the U.S. military’s currently issued M16 rifle and M4 carbine.
   If caseless ammunition advances to the point where it is comparable to traditional, brass-cased cartridges in price, performance and durability, a number of practical reasons would invite change.

The Crystal Ball
   A final try for an answer to the “when” question was once again met by Spiegel with the kind of cautious wisdom that comes from many years of experience. “We just don’t know because both cartridge types hold so much promise and there’s more work to be done,” she advised. “My assumption for LSAT’s transition to Program Manager Soldier Weapons is that it would not happen before 2010.”
   I didn’t ask Spiegel to speculate on how long it will take after her team’s finalized “best solution” gun and ammunition have been passed on to PMSW before the M249 is replaced. By this time I realized that it was just not a fair question. So I didn’t ask about ray guns, either.

  AAI’s website has a downloadable LSAT brochure and more at www.aaicorp.com. Click Advanced Programs then Lightweight Small Arms Technologies. A formal briefing on LSAT was presented at National Defense Industrial Association’s Small Arms Symposium. It may be found at www.dtic.mil/ndia/2007smallarms/5_9_07/Spiegel_820am.pdf.

BONUS LSAT coverage
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CASED TELESCOPED
WEAPON PROTOTYPE
SERIAL NUMBER 1

Integrated weapon: Textron Systems’ AAI Corp., Hunt Valley, MD

Operating mechanism:
ARES, Inc., Port Clinton, Ohio

Overall length: 36.1" with
stock retracted

Barrel: rifled length 16.5"
with six-groove rifling, 1:7" twist

Empty weight: 9.8 lbs.

Firing weight (with 200 rounds): 14.2 lbs.

Operation: open-bolt, semi-automatic and full automatic at 650 r.p.m.

System of operation/locking:
gas piston and swinging chamber

Ammunition: polymer cased with telescoped 5.56x45 mm M855 ball and M856 tracer

Ammunition weight: 4.4 lbs for 200 rounds packaged

Feed: push-through feed and ejection; full loop polymer linked belts

Muzzle velocity: 3020 f.p.s.
(same as M249 SAW)

Effective range: Same as M249

Innovative Mechanical Operation
   The LSAT CT SN1 operates with what program materials describe as a rotating chamber. It doesn’t go all the way around, but moves up and down in a precisely controlled arc of approximately 45 degrees. Not to pick a fight, but I am inclined to label this as a “swinging chamber.”
   Think of a clock face while looking at this photo of the open feed tray, shot from the gunner’s perspective. That shiny tunnel offset to the right is the swinging chamber, empty and at rest in the 12 o’clock position, ready to accept the leading round in the belt. Meanwhile, the barrel is waiting below at 9 o’clock.
   Pulling the trigger releases the rammer to push a cartridge into the chamber, which then swings counter-clockwise down to the 9 o’clock position, locking in line with the barrel. On firing, the plastic case is fully contained and supported so chamber pressure and resultant muzzle velocity equate to that of conventional systems.
   “Dwell time”—milliseconds delay allowing the cartridge to deflate for ease of ejection—occurs during the chamber’s clockwise return movement up to the feed tray. The empty plastic case is driven forward and expelled when the next cartridge is rammed. Its empty link is pushed out of the feedway as each new round in the belt is pulled into position.

A Look At Serial Number 1
   Its quick-change, 16.5"-long steel barrel is being tested in both smooth and fluted configurations. It has ordinary rifling inside and is currently tipped with a standard G.I. birdcage flash suppressor/muzzle compensator. There is nothing unusual in the gas block with a conventional expansion chamber forward of the piston. A dovetail base sits on top for attachment of a front sight if needed.
   A slightly futuristic look comes from distinctively angled cooling slots on the forward end of the receiver. Lengths of MIL STD 1913 rail on the sides and underneath are used to mount various accessories. A pair of tubes attached underneath facilitate mounting to both special test fixtures and standard issue tripods in the same manner as the current M249.
   The pistol grip/trigger housing mechanism is of conventional ergonomic design. Its left-side selector lever is thumbed downward from “SAFE” to “1” (semi-automatic) and “A” (full-automatic).
   The plastic loop belted polymer cartridges in a soft side assault pouch clipped underneath are fed from the left side like the M249 and most other U.S. machine guns. A hinged feed cover on top, about the size of a cigarette pack, swings open to reveal a pair of conventional feed pawls that move the linked ammunition in line with the chamber.
   Ridges on the feedplate and inside the cover reduce friction drag. Stripped links are pushed out the right side as each round is rammed forward and another moves in line with the chamber.
   The charging handle protrudes from a channel on the right side of the receiver. It is automatically returned to forward position by a coiled spring and guide rod and does not reciprocate on firing. As each new round is rammed into the chamber, the spent case is pushed forward and out the right side of the weapon through a prominent rectangular port in front of the feedway.
   Its skeletonized buttstock telescopes in the manner of an M4 carbine to adjust for body armor and different-size shooters. There is a hinged shoulder rest on its butt plate and a good gripping surface up front for the non-firing hand.
   Rigidly mounted at the top rear of the gun’s boxy receiver is a length of Picatinny Rail to accept most any type of sight. The one most often seen in demonstration photos is Trijicon’s 4X ACOG TA31 Advanced Combat Optical Sight, fitted with distinctive honeycomb anti-reflective cover and laser filter. On top is a Docter red dot for fast CQB shooting, shielded by protective wings.
   The weapon’s long stroke, soft recoil system comes from the Stoner/ARES Light Machine Gun and the resulting controllability is said to be well liked by those with bragging rights from shooting the prototype.

“Light” Machine Gun?
   The U.S. M249 Squad Automatic Weapon (SAW) is most often carried and used by one man in dismounted combat action. This 17.5-lb. SAW and its standard combat load of 600 rounds add a burden of more than 38 lbs. on top of the infantryman’s heavy body armor, water, rations and gear.
   While the SAW’s firepower is critical in many combat scenarios, something approaching a 50-percent reduction in combined weight will have to be achieved before the heavily laden SAW gunner will have mobility on a par with a brother rifleman.
   The challenge is reaching this goal without sacrificing the essential firepower, effective range and lethality that come from a truly light machine gun.