Lightweight Small Arms Technologies
Encyclopedia
The Lightweight Small Arms Technologies (LSAT) program is funded by the U.S. Joint Service Small Arms Program
, with the goal of significantly reducing the weight of small arms
and their ammunition
. Following a series of military programs to investigate advances in small arms (the SPIW program, the Future Rifle Program, the ACR
program, and the OICW program), the LSAT program is the US Military's latest project to replace existing US small arms. Tactical concepts and the research from the previous small arms programs indicates that lightening small arms is only the first significant step in small arms design towards increasing soldiers'
lethality and survivability.
Initiated in 2004 (then called the Lightweight Machine Gun and Ammunition program), development is now made by a team of eight companies led by AAI Corporation
. Development began with the two types of weight reducing ammunition, and a light machine gun
to serve as a testbed
and technology demonstrator. Use of an LMG for this purpose is notable, considering its greater technical complexity than infantry rifles. Minimization of program risk is shown by the development of the lower performing but less risky polymer-cased ammunition
alongside caseless ammunition
(which falls higher in both criteria), by the use of extensive computer simulations before prototyping, and by the use of existing and proven technologies, such as the HITP (High Ignition Temperature Propellant)—developed for Heckler & Koch's
G11
.
As of 2008, the program has achieved tremendous progress, with already operational prototypes for the polymer-cased ammunition and the LMG
that fires it. The less orthodox caseless ammunition is less than a year behind, and the design of a rifle firing both types of ammunition has already begun. The designers project further developments. These include improved projectile technologies, such as greener bullet
s and a more lethal caliber
, as well as the use of electronics, such as rounds
counters, and lasers for sighting, target acquisition, and steering. After further research and development into both ammunition types and the platforms that fire them, one of the two shall be chosen for production.
technologies, each program of which produced results that were infeasible or insignificant. The first three (the Special Purpose Individual Weapon
, the Future Rifle Program, and the Advanced Combat Rifle
program) demonstrated the ballistic problems of flechette
ammunition, and the ACR
program also showed the inability of kinetic-energy firearms to significantly compensate for human inaccuracy (the small accuracy increase of all of the concepts tested was out-weighed by the trade-offs required). The subsequent identification of programmable air-bursting munitions as the only way to significantly increase accuracy was followed by the fourth, and most recent, cancelled program—the OICW program. The ability to detonate an explosive in the air at range provided a huge increase in accuracy, but the resultant XM29 proved too heavy to use. The separation of the XM29 into the XM25
and the XM8 provided no long-term solution to the weight problem, and the program was suspended indefinitely. Developments in lighter weapons (such as LSAT) could see a return to the concept, although the military has not recently expressed a desire for a return. The indefinite suspension of the program sounded the death of short-term advances in infantry weapon lethality, and indicated the shift to other projects.
After the failure to significantly improve firearms of the near future, the U.S. military
is using the development of other infantry equipment to improve the effectiveness of the soldier. Most notable is the development of electronics
and information technology
to advance soldiers' awareness and communications (as with the Land Warrior
program). However, this new equipment increases the weight burden on the soldier, who then has to strike a compromise between the extra equipment and mobility. Reducing the weight of infantry equipment allows for more mobile, better equipped troops. Since a soldier's weapon and ammunition are a large portion of his total burden (and available technologies exist to sharply lighten them), reducing the weight of the two is crucial to increasing the amount of advanced technology a soldier can carry. Computer technologies integrated into the weapon and its sights make a light weapon crucial, otherwise the soldier shall have difficulty carrying the weapon and its heavy sights. Other indirect improvements in soldier effectiveness include new strategies and the development of air transport. This is aimed towards creating fast, well-equipped soldiers able to be quickly deployed to counter threats. The logistics and mobility problems of heavy equipment hinder this possibility.
The LSAT program allows a vast reduction in soldiers' carrying loads, thereby allowing new and more equipment, reducing logistical strain, and increasing mobility. The combined benefits to soldier effectiveness are big enough to warrant the investment in the new lightweight technologies.
varieties. The Heckler & Koch
G11
was the only weapon to achieve a service capable assault rifle firing caseless ammunition. Its unique ammunition, designed by Dynamit Nobel, introduced several important innovations, such as improved internal ballistics through the use of a primer, and the prevention of cooking off
(the lack of a case makes it easier for a hot chamber to ignite the exposed propellant) through the use of the less sensitive hexogen/octogen as the explosive component. The Advanced Combat Rifle
experimental program gave the US Army access to the ammunition and entrenched the ammunition as a viable option. With the high efficiency and lethality of the ammunition, the vast expenditure such a concept had needed for development, and the reduced risk of using an already proven ammunition design, the LSAT program chose a licensed version of Dynamit Nobel's caseless ammunition as a route towards its goal of weight reduction. The LSAT program also uses the same concept of a rotating chamber as the G11 (albeit, the LSAT LMG
chamber swings around a longitudinal pivot. whereas the G11 chamber rotated around a horizontal axis at its very centre).
Polymer casing for ammunition had already been developed and produced, and it provided the second route for achieving weight reduction. While a polymer case could never be quite as light as no case, the risks involved in the use of polymer ammunition were less, due to its similarity to present ammunition and the reduced heat load on both the weapon and the ammunition's propellant.
Further budding technologies, such as alternative barrel materials (such as ceramic
s), and the increased efficiency and size reduction of telescoped ammunition (used by the G11 and other developmental weapons), also formed the basis for the LSAT program.
created the Lightweight Machine Gun and Ammunition program to compare conceptual, lightweight machine guns and ammunition designs by two teams of companies. The team of eight, led by AAI Corporation
had their design chosen over the design of the General Dynamics-led team. In 2005, the project was replaced with the Lightweight Small Arms Technologies program to place the emphasis on developing technologies for a wide range of small arms. The earlier Lightweight Family of Weapons and Ammunition concept is visible in the new program. The cohesive team of companies is combined with government support to ensure success.
In accordance with the program's name, the focus is on creating lightweight technologies for all small arms, and the Light Machine Gun
it has started with is an entry point for a family of lightweight small arms and ammunition. Beginning with an LMG is unusual for an effort to develop a new family of weapons, although the increased engineering difficulty of a machine gun over a rifle is balanced against decreased attention and antagonistic scrutiny. The program minimized development risk: it used G11 technology that had been on the verge of deployment; and the parallel development of the composite-cased and caseless ammunition meant that, if the caseless ammunition effort succeeded, much of the development work gained with the composite cased weapon could be applied to it, and, if it failed, the composite-cased version was likely to succeed on its own. This parallel development involves using what is essentially the same weapon for both types of ammunition, with the same action (having only marginal differences, such as added chamber sealing technologies required for the caseless firing version) and the same weight-lowering technologies. The program uses extensive computer simulation and modelling, particularly of the weapon action. This reduces both time and expenditure for prototyping and testing. The program also uses a 'spiral development' approach, whereby the weapon and ammunition is rolled out in stages or 'spirals', each stage producing a new version that is an improvement on those from previous spirals.
The LSAT program uses a 'clean slate' design and had no requirements imposed on abiding by contemporary ammunition and weapon standards. Despite this, the program is using the M855 5.56x45mm round to provide comparison with existing weapons. The program has listed scalability of the ammunition calibre as a requirement, and its pursuit of a very light company machine gun would require a larger round. Therefore, the program seems set towards a more accurate, harder-hitting round (such as the 6.5 mm Grendel or 6.8mm Remington SPC).
The program has set itself weight reduction goals over the existing M249 and its ammunition of 35% for the weapon and 40% for the ammunition. Further goals to improve battlefield effectiveness have also been set: improved lethality; improved controllability (through recoil reduction, etc.); improved ergonomics; improved reliability and maintainability; integration of electronics; and equivalent cost and producibility to the existing weapon and ammunition.
s built made a 47% and 43% reduction of weight for the caseless weapon and cased telescoped weapons, respectively. The more complex chamber-sealing mechanism of the caseless weapon somewhat increases its weight compared to the composite-cased weapon Secondary goals have also been met: the LMG has the potential to improve battlefield effectiveness (due to its simpler and more consistent weapon action, its light weight and low recoil, and its stiffer barrel); its use of recoil compensation (with a long-stroke gas-system, for example) has produced positive feedback regarding controllability; the simpler mechanism of the LMG is both more reliable and easier to maintain; a rounds counter has been integrated to improve maintainability, and the weapon is capable of accepting other electronic devices; improved materials used in the chamber and barrel have reduced heat load on the weapon; and the weapon cost is equivalent to the existing M249.
The LMG design is a traditionally (non-bullpup
) laid-out machine-gun. It has many of the capabilities of other light machine guns, such as a quick-change barrel, a vented fore-grip, belt-fed ammunition, an ammunition pouch, and a roughly 600 rpm rate of fire
. New features include the unique weight of 9.2 pounds for CT and 9.9 pounds for CL, a rounds counter, and a highly stiff and heat resistant barrel achieved with fluting and special materials. Possibly the most radical part is its firing action: the weapon uses a swinging chamber. The chamber swings around a longitudinal pivot; it swings from horizontally parallel with the pivot (the firing position), to vertically parallel (the feed position), and back again. A long-stroke gas-piston is used to operate this action. A round is fed into the chamber at the feed position using a rammer, and the new round also serves to push a spent or dud round out of the far end of the chamber. Such rounds are pushed forward, parallel to the barrel, and they slide into a separate mechanism that ejects them out of one side of the gun. The advantages of this whole action include its simplicity, its isolation of the chamber from barrel heat, and its positive control of round movement from extraction to ejection. In the caseless firing version of the weapon, another mechanism is introduced to seal the chamber during firing (which is why the caseless weapon is heavier).
layout, since the forward ejection of the push-through feed-and-ejection mechanism could easily be extended to achieve full ambidexterity, which is a problematic absence in most bullpups. Even in other configurations, the push-through mechanism lends itself very well to ambidexterity
: the G11
demonstrates this. The rifle designs are undergoing the same simulated, structural, and kinematic analyses as the LMG.
weapons.
of 5. As of 2008, the cased ammunition has been tested for a wide range of operating temperature
s, and it has had over 9000 rounds fired (approximately 6500 rounds of Spiral 1 ammunition, and over 2000 of Spiral 2). The second spiral version of the cased ammunition produced a 33% weight reduction (falling just short of the program goal), while the ongoing development of the third spiral of cased ammunition has achieved a roughly 40% reduction. The third spiral is also 30% smaller than standard ammunition. The improvement by the third spiral of cased ammunition over the second spiral was achieved partially by compacting and consolidating the propellant (thereby allowing a smaller cartridge case and round). Having reached a sufficient technology readiness level
, the Spiral 2 ammunition is being prepared for a contracted 2000 round delivery. The cased ammunition has shown itself as a virtually risk free option, with present and potential ability grounded in success. In addition, development of the cased ammunition firing weapon has significantly improved understanding of the weapon action and requirements.
ammunition, the HITP (High Ignition Temperature Propellant—it is hexogen/octogen based to decrease heat sensitivity) based ammunition was modified to a 5.56 mm round. Tests proved the ammunition's usability, and development of the weapon was advanced using knowledge gained from the cased ammunition version. The Alliant Techsystems
ammunition production team has reduced the production time and costs by reducing from fourteen to two the number of steps used to complete processing. The second spiral of caseless ammunition was rolled out in 2008, with the necessary facilities to produce the ammunition in bulk completed. It has vastly reduced the weight and volume of standard ammunition (by 51% and 40%, respectively), and it has reached the verge of achieving Technology Readiness Level 5. The development of the third spiral was also initiated, with the goal of replacing the propellant binder with a binder more environmentally and cost friendly. It also aims to reduce the heat ablation on the inside of the weapon by modifying the burn rate of the propellant, and by giving the round an exterior coating to absorb or prevent transferred heat. Benefits the system has gained from using the caseless ammunition go beyond the unparalleled weight and volume reduction to, for example, the lack of ejected shells (which both improves the weapon's protection from dirt and removes any need to 'police' cases after firing).
Joint Service Small Arms Program
The Joint Service Small Arms Program, abbreviated JSSAP, was created to coordinate weapon standardization between the various U.S. armed service branches....
, with the goal of significantly reducing the weight of small arms
Small arms
Small arms is a term of art used by armed forces to denote infantry weapons an individual soldier may carry. The description is usually limited to revolvers, pistols, submachine guns, carbines, assault rifles, battle rifles, multiple barrel firearms, sniper rifles, squad automatic weapons, light...
and their ammunition
Ammunition
Ammunition is a generic term derived from the French language la munition which embraced all material used for war , but which in time came to refer specifically to gunpowder and artillery. The collective term for all types of ammunition is munitions...
. Following a series of military programs to investigate advances in small arms (the SPIW program, the Future Rifle Program, the ACR
Advanced Combat Rifle
The Advanced Combat Rifle was a United States Army program to find a replacement for the M16 assault rifle. The program's total cost is approximately US$300 million...
program, and the OICW program), the LSAT program is the US Military's latest project to replace existing US small arms. Tactical concepts and the research from the previous small arms programs indicates that lightening small arms is only the first significant step in small arms design towards increasing soldiers'
Soldier
A soldier is a member of the land component of national armed forces; whereas a soldier hired for service in a foreign army would be termed a mercenary...
lethality and survivability.
Initiated in 2004 (then called the Lightweight Machine Gun and Ammunition program), development is now made by a team of eight companies led by AAI Corporation
AAI Corporation
AAI Corporation is an aerospace and defense development and manufacturing firm in Hunt Valley, Maryland, USA. It is formerly a wholly owned subsidiary of United Industrial Corporation, AAI was acquired by Textron in 2007 and currently is an operating unit of Textron Systems Corporation...
. Development began with the two types of weight reducing ammunition, and a light machine gun
Light machine gun
A light machine gun is a machine gun designed to be employed by an individual soldier, with or without an assistant, as an infantry support weapon. Light machine guns are often used as squad automatic weapons.-Characteristics:...
to serve as a testbed
Testbed
A testbed is a platform for experimentation of large development projects. Testbeds allow for rigorous, transparent, and replicable testing of scientific theories, computational tools, and new technologies.The term is used across many disciplines to describe a development environment that is...
and technology demonstrator. Use of an LMG for this purpose is notable, considering its greater technical complexity than infantry rifles. Minimization of program risk is shown by the development of the lower performing but less risky polymer-cased ammunition
Polymer-cased ammunition
-Overview:A plastic cylinder makes up the body of the cartridge. Starting from the back of the interior of the cartridge: The primer material. A priming method for rimfire cartridges is disclosed in which a propellant solution is disposed adjacent a centrifugally located primer material in a...
alongside caseless ammunition
LSAT caseless ammunition
LSAT caseless ammunition is caseless ammunition produced as part of the U.S. Army’s Lightweight Small Arms Technologies program.Although less advanced in development than the other ammunition component of the program, the caseless round has already produced its own outstanding results...
(which falls higher in both criteria), by the use of extensive computer simulations before prototyping, and by the use of existing and proven technologies, such as the HITP (High Ignition Temperature Propellant)—developed for Heckler & Koch's
Heckler & Koch
Heckler & Koch GmbH is a German defense manufacturing company that produces various small arms. Some of their products include the SA80, MP5 submachine gun, G3 automatic rifle, the G36 assault rifle, the HK 416, the MP7 personal defense weapon, the USP series of handguns, and the high-precision...
G11
Heckler & Koch G11
The Heckler & Koch G11 is a non-production prototype assault rifle developed during the late 1960s, 1970s and 1980s by Gesellschaft für Hülsenlose Gewehrsysteme , a conglomeration of companies headed by firearm manufacturer Heckler & Koch , Dynamit Nobel The Heckler & Koch G11 is a non-production...
.
As of 2008, the program has achieved tremendous progress, with already operational prototypes for the polymer-cased ammunition and the LMG
Light machine gun
A light machine gun is a machine gun designed to be employed by an individual soldier, with or without an assistant, as an infantry support weapon. Light machine guns are often used as squad automatic weapons.-Characteristics:...
that fires it. The less orthodox caseless ammunition is less than a year behind, and the design of a rifle firing both types of ammunition has already begun. The designers project further developments. These include improved projectile technologies, such as greener bullet
Bullet
A bullet is a projectile propelled by a firearm, sling, or air gun. Bullets do not normally contain explosives, but damage the intended target by impact and penetration...
s and a more lethal caliber
Caliber
In guns including firearms, caliber or calibre is the approximate internal diameter of the barrel in relation to the diameter of the projectile used in it....
, as well as the use of electronics, such as rounds
Bullet
A bullet is a projectile propelled by a firearm, sling, or air gun. Bullets do not normally contain explosives, but damage the intended target by impact and penetration...
counters, and lasers for sighting, target acquisition, and steering. After further research and development into both ammunition types and the platforms that fire them, one of the two shall be chosen for production.
Program background
The Lightweight Small Arms Technologies program is the culmination of much research and information obtained by the US Army. It succeeds several other programs to develop new small armsSmall arms
Small arms is a term of art used by armed forces to denote infantry weapons an individual soldier may carry. The description is usually limited to revolvers, pistols, submachine guns, carbines, assault rifles, battle rifles, multiple barrel firearms, sniper rifles, squad automatic weapons, light...
technologies, each program of which produced results that were infeasible or insignificant. The first three (the Special Purpose Individual Weapon
Special Purpose Individual Weapon
The Special Purpose Individual Weapon was a long-running United States Army program to develop, in part, a workable flechette-based "rifle", though other concepts were also involved...
, the Future Rifle Program, and the Advanced Combat Rifle
Advanced Combat Rifle
The Advanced Combat Rifle was a United States Army program to find a replacement for the M16 assault rifle. The program's total cost is approximately US$300 million...
program) demonstrated the ballistic problems of flechette
Flechette
A flechette is a pointed steel projectile, with a vaned tail for stable flight. The name comes from French , "little arrow" or "dart", and sometimes retains the acute accent in English: fléchette.-Bulk and artillery use:...
ammunition, and the ACR
Advanced Combat Rifle
The Advanced Combat Rifle was a United States Army program to find a replacement for the M16 assault rifle. The program's total cost is approximately US$300 million...
program also showed the inability of kinetic-energy firearms to significantly compensate for human inaccuracy (the small accuracy increase of all of the concepts tested was out-weighed by the trade-offs required). The subsequent identification of programmable air-bursting munitions as the only way to significantly increase accuracy was followed by the fourth, and most recent, cancelled program—the OICW program. The ability to detonate an explosive in the air at range provided a huge increase in accuracy, but the resultant XM29 proved too heavy to use. The separation of the XM29 into the XM25
XM25
The XM25 Counter Defilade Target Engagement System, also known as the Punisher, Individual Semiautomatic Air Burst System, and the Bowling Tube is an air burst grenade launcher derived from the XM29 OICW...
and the XM8 provided no long-term solution to the weight problem, and the program was suspended indefinitely. Developments in lighter weapons (such as LSAT) could see a return to the concept, although the military has not recently expressed a desire for a return. The indefinite suspension of the program sounded the death of short-term advances in infantry weapon lethality, and indicated the shift to other projects.
After the failure to significantly improve firearms of the near future, the U.S. military
United States armed forces
The United States Armed Forces are the military forces of the United States. They consist of the Army, Navy, Marine Corps, Air Force, and Coast Guard.The United States has a strong tradition of civilian control of the military...
is using the development of other infantry equipment to improve the effectiveness of the soldier. Most notable is the development of electronics
Electronics
Electronics is the branch of science, engineering and technology that deals with electrical circuits involving active electrical components such as vacuum tubes, transistors, diodes and integrated circuits, and associated passive interconnection technologies...
and information technology
Information technology
Information technology is the acquisition, processing, storage and dissemination of vocal, pictorial, textual and numerical information by a microelectronics-based combination of computing and telecommunications...
to advance soldiers' awareness and communications (as with the Land Warrior
Land Warrior
Land Warrior is a United States Army program, cancelled in 2007, that was to use a combination of commercial, off-the-shelf technology and current-issue military gear and equipment designed to:* integrate small arms with high-tech equipment;...
program). However, this new equipment increases the weight burden on the soldier, who then has to strike a compromise between the extra equipment and mobility. Reducing the weight of infantry equipment allows for more mobile, better equipped troops. Since a soldier's weapon and ammunition are a large portion of his total burden (and available technologies exist to sharply lighten them), reducing the weight of the two is crucial to increasing the amount of advanced technology a soldier can carry. Computer technologies integrated into the weapon and its sights make a light weapon crucial, otherwise the soldier shall have difficulty carrying the weapon and its heavy sights. Other indirect improvements in soldier effectiveness include new strategies and the development of air transport. This is aimed towards creating fast, well-equipped soldiers able to be quickly deployed to counter threats. The logistics and mobility problems of heavy equipment hinder this possibility.
The LSAT program allows a vast reduction in soldiers' carrying loads, thereby allowing new and more equipment, reducing logistical strain, and increasing mobility. The combined benefits to soldier effectiveness are big enough to warrant the investment in the new lightweight technologies.
Background technologies
The existence of weight-reducing technologies made the LSAT program feasible, and many of these technologies can be seen in the program's products. The lightest existing ammunition to fire standard bullets comprised caselessCaseless ammunition
Caseless ammunition is a type of small arms ammunition that eliminates the cartridge case that typically holds the primer, propellant, and projectile together as a unit...
varieties. The Heckler & Koch
Heckler & Koch
Heckler & Koch GmbH is a German defense manufacturing company that produces various small arms. Some of their products include the SA80, MP5 submachine gun, G3 automatic rifle, the G36 assault rifle, the HK 416, the MP7 personal defense weapon, the USP series of handguns, and the high-precision...
G11
Heckler & Koch G11
The Heckler & Koch G11 is a non-production prototype assault rifle developed during the late 1960s, 1970s and 1980s by Gesellschaft für Hülsenlose Gewehrsysteme , a conglomeration of companies headed by firearm manufacturer Heckler & Koch , Dynamit Nobel The Heckler & Koch G11 is a non-production...
was the only weapon to achieve a service capable assault rifle firing caseless ammunition. Its unique ammunition, designed by Dynamit Nobel, introduced several important innovations, such as improved internal ballistics through the use of a primer, and the prevention of cooking off
Cooking off
Cooking off refers to ammunition exploding prematurely due to heat in the surrounding environment. It can also refer to a technique used when throwing grenades to achieve a controlled, predictable explosion....
(the lack of a case makes it easier for a hot chamber to ignite the exposed propellant) through the use of the less sensitive hexogen/octogen as the explosive component. The Advanced Combat Rifle
Advanced Combat Rifle
The Advanced Combat Rifle was a United States Army program to find a replacement for the M16 assault rifle. The program's total cost is approximately US$300 million...
experimental program gave the US Army access to the ammunition and entrenched the ammunition as a viable option. With the high efficiency and lethality of the ammunition, the vast expenditure such a concept had needed for development, and the reduced risk of using an already proven ammunition design, the LSAT program chose a licensed version of Dynamit Nobel's caseless ammunition as a route towards its goal of weight reduction. The LSAT program also uses the same concept of a rotating chamber as the G11 (albeit, the LSAT LMG
Light machine gun
A light machine gun is a machine gun designed to be employed by an individual soldier, with or without an assistant, as an infantry support weapon. Light machine guns are often used as squad automatic weapons.-Characteristics:...
chamber swings around a longitudinal pivot. whereas the G11 chamber rotated around a horizontal axis at its very centre).
Polymer casing for ammunition had already been developed and produced, and it provided the second route for achieving weight reduction. While a polymer case could never be quite as light as no case, the risks involved in the use of polymer ammunition were less, due to its similarity to present ammunition and the reduced heat load on both the weapon and the ammunition's propellant.
Further budding technologies, such as alternative barrel materials (such as ceramic
Ceramic
A ceramic is an inorganic, nonmetallic solid prepared by the action of heat and subsequent cooling. Ceramic materials may have a crystalline or partly crystalline structure, or may be amorphous...
s), and the increased efficiency and size reduction of telescoped ammunition (used by the G11 and other developmental weapons), also formed the basis for the LSAT program.
Program beginning
In 2004, the Joint Service Small Arms ProgramJoint Service Small Arms Program
The Joint Service Small Arms Program, abbreviated JSSAP, was created to coordinate weapon standardization between the various U.S. armed service branches....
created the Lightweight Machine Gun and Ammunition program to compare conceptual, lightweight machine guns and ammunition designs by two teams of companies. The team of eight, led by AAI Corporation
AAI Corporation
AAI Corporation is an aerospace and defense development and manufacturing firm in Hunt Valley, Maryland, USA. It is formerly a wholly owned subsidiary of United Industrial Corporation, AAI was acquired by Textron in 2007 and currently is an operating unit of Textron Systems Corporation...
had their design chosen over the design of the General Dynamics-led team. In 2005, the project was replaced with the Lightweight Small Arms Technologies program to place the emphasis on developing technologies for a wide range of small arms. The earlier Lightweight Family of Weapons and Ammunition concept is visible in the new program. The cohesive team of companies is combined with government support to ensure success.
In accordance with the program's name, the focus is on creating lightweight technologies for all small arms, and the Light Machine Gun
Light machine gun
A light machine gun is a machine gun designed to be employed by an individual soldier, with or without an assistant, as an infantry support weapon. Light machine guns are often used as squad automatic weapons.-Characteristics:...
it has started with is an entry point for a family of lightweight small arms and ammunition. Beginning with an LMG is unusual for an effort to develop a new family of weapons, although the increased engineering difficulty of a machine gun over a rifle is balanced against decreased attention and antagonistic scrutiny. The program minimized development risk: it used G11 technology that had been on the verge of deployment; and the parallel development of the composite-cased and caseless ammunition meant that, if the caseless ammunition effort succeeded, much of the development work gained with the composite cased weapon could be applied to it, and, if it failed, the composite-cased version was likely to succeed on its own. This parallel development involves using what is essentially the same weapon for both types of ammunition, with the same action (having only marginal differences, such as added chamber sealing technologies required for the caseless firing version) and the same weight-lowering technologies. The program uses extensive computer simulation and modelling, particularly of the weapon action. This reduces both time and expenditure for prototyping and testing. The program also uses a 'spiral development' approach, whereby the weapon and ammunition is rolled out in stages or 'spirals', each stage producing a new version that is an improvement on those from previous spirals.
The LSAT program uses a 'clean slate' design and had no requirements imposed on abiding by contemporary ammunition and weapon standards. Despite this, the program is using the M855 5.56x45mm round to provide comparison with existing weapons. The program has listed scalability of the ammunition calibre as a requirement, and its pursuit of a very light company machine gun would require a larger round. Therefore, the program seems set towards a more accurate, harder-hitting round (such as the 6.5 mm Grendel or 6.8mm Remington SPC).
The program has set itself weight reduction goals over the existing M249 and its ammunition of 35% for the weapon and 40% for the ammunition. Further goals to improve battlefield effectiveness have also been set: improved lethality; improved controllability (through recoil reduction, etc.); improved ergonomics; improved reliability and maintainability; integration of electronics; and equivalent cost and producibility to the existing weapon and ammunition.
Program achievements
By 2008, the program had made tremendous progress, with all of its goals either fully achieved or with strong potential for achievement.Light Machine Gun
The LMGLight machine gun
A light machine gun is a machine gun designed to be employed by an individual soldier, with or without an assistant, as an infantry support weapon. Light machine guns are often used as squad automatic weapons.-Characteristics:...
s built made a 47% and 43% reduction of weight for the caseless weapon and cased telescoped weapons, respectively. The more complex chamber-sealing mechanism of the caseless weapon somewhat increases its weight compared to the composite-cased weapon Secondary goals have also been met: the LMG has the potential to improve battlefield effectiveness (due to its simpler and more consistent weapon action, its light weight and low recoil, and its stiffer barrel); its use of recoil compensation (with a long-stroke gas-system, for example) has produced positive feedback regarding controllability; the simpler mechanism of the LMG is both more reliable and easier to maintain; a rounds counter has been integrated to improve maintainability, and the weapon is capable of accepting other electronic devices; improved materials used in the chamber and barrel have reduced heat load on the weapon; and the weapon cost is equivalent to the existing M249.
The LMG design is a traditionally (non-bullpup
Bullpup
Bullpups are firearm configurations in which the action is located behind the trigger group and alongside the shooter's face, so there is no wasted space for the buttstock as in conventional designs. This permits a shorter firearm length for the same barrel length for improved maneuverability, and...
) laid-out machine-gun. It has many of the capabilities of other light machine guns, such as a quick-change barrel, a vented fore-grip, belt-fed ammunition, an ammunition pouch, and a roughly 600 rpm rate of fire
Rate of fire
Rate of fire is the frequency at which a specific weapon can fire or launch its projectiles. It is usually measured in rounds per minute , or per second .-Overview:...
. New features include the unique weight of 9.2 pounds for CT and 9.9 pounds for CL, a rounds counter, and a highly stiff and heat resistant barrel achieved with fluting and special materials. Possibly the most radical part is its firing action: the weapon uses a swinging chamber. The chamber swings around a longitudinal pivot; it swings from horizontally parallel with the pivot (the firing position), to vertically parallel (the feed position), and back again. A long-stroke gas-piston is used to operate this action. A round is fed into the chamber at the feed position using a rammer, and the new round also serves to push a spent or dud round out of the far end of the chamber. Such rounds are pushed forward, parallel to the barrel, and they slide into a separate mechanism that ejects them out of one side of the gun. The advantages of this whole action include its simplicity, its isolation of the chamber from barrel heat, and its positive control of round movement from extraction to ejection. In the caseless firing version of the weapon, another mechanism is introduced to seal the chamber during firing (which is why the caseless weapon is heavier).
Assault rifle
Design of an LSAT battle rifle began in 2008. Half way into 2008, the designs are nearing completion. The rifle designs are made to use the same cartridge as developed for the LMG, and this means separate rifles are being designed for the cased and caseless cartridges. Design began with seventeen concepts; after the concepts were investigated and trade-offs were analysed, only two remained for the cased round, and two for the caseless round. The concepts involve two magazine approaches, both of which are focussed on high capacity: one uses the standard approach of placing inside the magazine springs that feed rounds into the weapon; the other uses a 'weapon powered' approach, presumably to reduce the extra weight and space that springs create in magazines. If any of the rifle designs use the same swinging chamber mechanism as the LMG, they should be well suited to a bullpupBullpup
Bullpups are firearm configurations in which the action is located behind the trigger group and alongside the shooter's face, so there is no wasted space for the buttstock as in conventional designs. This permits a shorter firearm length for the same barrel length for improved maneuverability, and...
layout, since the forward ejection of the push-through feed-and-ejection mechanism could easily be extended to achieve full ambidexterity, which is a problematic absence in most bullpups. Even in other configurations, the push-through mechanism lends itself very well to ambidexterity
Ambidexterity
Ambidexterity is the state of being equally adept in the use of both left and right appendages . It is one of the most famous varieties of cross-dominance. People that are naturally ambidextrous are rare, with only one out of one hundred people being naturally ambidextrous...
: the G11
Heckler & Koch G11
The Heckler & Koch G11 is a non-production prototype assault rifle developed during the late 1960s, 1970s and 1980s by Gesellschaft für Hülsenlose Gewehrsysteme , a conglomeration of companies headed by firearm manufacturer Heckler & Koch , Dynamit Nobel The Heckler & Koch G11 is a non-production...
demonstrates this. The rifle designs are undergoing the same simulated, structural, and kinematic analyses as the LMG.
Ammunition
The cylindrical shape of the ammunition is crucial to the weapon's straight-through feed-and-ejection system, and it is the similar shape of the cased-telescoped ammunition to the caseless-telescoped ammunition that allows the parallel development of the two weapon systems. Telescoped ammunition's most notable benefits include the greater propulsive effectiveness of a telescoped round over standard ammunition, and the shorter feed and action times allowed by the shorter length of a telescoped round (both the cased and caseless designs are roughly 30% shorter). If the weapon and amunition prove superior to existing weapons, a new caliber may be chosen. An intermediate round with characteristics similar to the 6.5 mm Grendel is being considered along with the possibility of using a common round in more roles including GPMG and marksmanMarksman
A marksman is a person who is skilled in precision, or a sharpshooter shooting, using projectile weapons, such as with a rifle but most commonly with a sniper rifle, to shoot at long range targets...
weapons.
Cased ammunition
The cased ammunition is more advanced in development, partially due to the fewer technical difficulties and the fewer differences with standard ammunition. It has already reached the required technology readiness levelTechnology Readiness Level
Technology Readiness Level is a measure used by some United States government agencies and many of the world's major companies to assess the maturity of evolving technologies prior to incorporating that technology into a system or subsystem...
of 5. As of 2008, the cased ammunition has been tested for a wide range of operating temperature
Operating temperature
An operating temperature is the temperature at which an electrical or mechanical device operates. The device will operate effectively within a specified temperature range which varies based on the device function and application context, and ranges from the minimum operating temperature to the...
s, and it has had over 9000 rounds fired (approximately 6500 rounds of Spiral 1 ammunition, and over 2000 of Spiral 2). The second spiral version of the cased ammunition produced a 33% weight reduction (falling just short of the program goal), while the ongoing development of the third spiral of cased ammunition has achieved a roughly 40% reduction. The third spiral is also 30% smaller than standard ammunition. The improvement by the third spiral of cased ammunition over the second spiral was achieved partially by compacting and consolidating the propellant (thereby allowing a smaller cartridge case and round). Having reached a sufficient technology readiness level
Technology Readiness Level
Technology Readiness Level is a measure used by some United States government agencies and many of the world's major companies to assess the maturity of evolving technologies prior to incorporating that technology into a system or subsystem...
, the Spiral 2 ammunition is being prepared for a contracted 2000 round delivery. The cased ammunition has shown itself as a virtually risk free option, with present and potential ability grounded in success. In addition, development of the cased ammunition firing weapon has significantly improved understanding of the weapon action and requirements.
Caseless ammunition
Although less advanced in development, the caseless round has already produced its own outstanding results. Having replicated Dynamit Nobel's ACRAdvanced Combat Rifle
The Advanced Combat Rifle was a United States Army program to find a replacement for the M16 assault rifle. The program's total cost is approximately US$300 million...
ammunition, the HITP (High Ignition Temperature Propellant—it is hexogen/octogen based to decrease heat sensitivity) based ammunition was modified to a 5.56 mm round. Tests proved the ammunition's usability, and development of the weapon was advanced using knowledge gained from the cased ammunition version. The Alliant Techsystems
Alliant Techsystems
Alliant Techsystems Inc., most commonly known by its ticker symbol, ', is one of the largest aerospace and defense companies in the United States with more than 18,000 employees in 22 states, Puerto Rico and internationally, and 2010 revenues in excess of an estimated...
ammunition production team has reduced the production time and costs by reducing from fourteen to two the number of steps used to complete processing. The second spiral of caseless ammunition was rolled out in 2008, with the necessary facilities to produce the ammunition in bulk completed. It has vastly reduced the weight and volume of standard ammunition (by 51% and 40%, respectively), and it has reached the verge of achieving Technology Readiness Level 5. The development of the third spiral was also initiated, with the goal of replacing the propellant binder with a binder more environmentally and cost friendly. It also aims to reduce the heat ablation on the inside of the weapon by modifying the burn rate of the propellant, and by giving the round an exterior coating to absorb or prevent transferred heat. Benefits the system has gained from using the caseless ammunition go beyond the unparalleled weight and volume reduction to, for example, the lack of ejected shells (which both improves the weapon's protection from dirt and removes any need to 'police' cases after firing).
See also
- MR-CMR-CThe Modular Rifle - Caseless , is a mock-up of an assault rifle that was intended to be manufactured and sold to the United States military as a next-generation infantry weapon firing next-generation ammunition. It has not been developed—even in prototype form—and the weapon was never lined-up for...
- Heckler & Koch G11Heckler & Koch G11The Heckler & Koch G11 is a non-production prototype assault rifle developed during the late 1960s, 1970s and 1980s by Gesellschaft für Hülsenlose Gewehrsysteme , a conglomeration of companies headed by firearm manufacturer Heckler & Koch , Dynamit Nobel The Heckler & Koch G11 is a non-production...
- Gerasimenko VAG-73Gerasimenko VAG-73The Gerasimenko VAG-73 is a Russian pistol capable of firing caseless bullets from a 48 round grip-inserted magazine....
- Future Force WarriorFuture Force WarriorFuture Force Warrior is a United States military advanced technology demonstration project that is part of the Future Combat Systems project. The FFW project seeks to create a lightweight, fully integrated infantryman combat system. It is one technology demonstration project in a series of...
- Future Combat SystemsFuture Combat SystemsFuture Combat Systems was the United States Army's principal modernization program from 2003 to early 2009. Formally launched in 2003, FCS was envisioned to create new brigades equipped with new manned and unmanned vehicles linked by an unprecedented fast and flexible battlefield network...
External links
- http://www.army.mil/-news/2010/07/29/42987-reducing-soldier-load-one-round-at-a-time-ardec-lightweight-technologies-slash-weight-in-half/
- http://kitup.military.com/2010/07/army-closer-to-era-of-lightweight-ammo.html
- http://www.scribd.com/doc/26503475/Lightweight-Small-Arms-Technologies
- Defense Update.
- http://www.docstoc.com/docs/28793754/Lightweight-Small-Arms-Technologies