LSAT light machine gun
Encyclopedia
The LSAT light machine gun, of the LSAT (Lightweight Small Arms Technologies
) program, is a developmental light machine gun
. The program was initiated in 2004, when the Joint Service Small Arms Program
(JSSAP) challenged the American
defence industry to develop lighter small arms
and ammunition
. The LMG
provides a major reduction in weight over legacy weapons, as well as improvements in other areas, such as controllability and reliability. As of 2008, it has two configurations, one that fires polymer-cased ammunition, and one that fires caseless ammunition
. After further research and development into both technologies and the platforms that fire them, one of the two variants shall be chosen for production.
and technology demonstrator. Use of an LMG for this purpose is notable, considering its greater technical complexity than infantry rifles. The use of advanced computer simulations to accelerate development may have mitigated this, and the less significant LMG platform succeeds at being less conspicuous to unwanted media attention. For development, the use of extensive computer simulation and modelling 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. A competition down-selected the design concepts of various companies to leave an AAI Corporation-led team of companies as the developers of the weapon system. The cohesive team of companies is combined with government support to ensure success. The parallel development of the two ammunition types 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.
s built made a 44% and 43% reduction of weight (for the cased telescoped and the caseless weapons, respectively). 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, 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 roughly 1% heavier).
Lightweight Small Arms Technologies
The Lightweight Small Arms Technologies 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...
) program, is a developmental 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:...
. The program was initiated in 2004, when the Joint Service Small Arms Program
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....
(JSSAP) challenged the American
United States
The United States of America is a federal constitutional republic comprising fifty states and a federal district...
defence industry to develop lighter 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 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...
. 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:...
provides a major reduction in weight over legacy weapons, as well as improvements in other areas, such as controllability and reliability. As of 2008, it has two configurations, one that fires polymer-cased ammunition, and one that fires 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...
. After further research and development into both technologies and the platforms that fire them, one of the two variants shall be chosen for production.
History
Development began with the two types of weight-reducing ammunition, and a light machine gun to serve as a testbedTestbed
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. The use of advanced computer simulations to accelerate development may have mitigated this, and the less significant LMG platform succeeds at being less conspicuous to unwanted media attention. For development, the use of extensive computer simulation and modelling 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. A competition down-selected the design concepts of various companies to leave an AAI Corporation-led team of companies as the developers of the weapon system. The cohesive team of companies is combined with government support to ensure success. The parallel development of the two ammunition types 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.
Details
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 44% and 43% reduction of weight (for the cased telescoped and the caseless weapons, respectively). 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, 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 roughly 1% heavier).