Sunday, August 10, 2014

Light Machine Guns

In our discussion about general features of machine guns, we discussed different classes of machine guns. Today, we will study the first of those classes, the light machine gun (often abbreviated as LMG).

Light machine guns were originally developed to support infantry squads, by providing short bursts of suppressive fire, designed to keep the enemy's heads down and allow friendly soldiers to advance. The first light machine guns were developed around World War I. Early machine gun examples include the Browning BAR M1918, Lewis gun, Madsen machine gun etc. In present day military forces, many infantry units carry one LMG per fire team or squad.

Browning Automatic Rifle (BAR) M1918, designed during World War I. Click on the image to enlarge. Public domain image.

A Lewis gun. Click on the image to enlarge. Public domain image.

The word "light" is a bit of a misnomer, because most LMGs are heavier than the assault rifles that the rest of the team carries. However, they are lighter than the other classes of machine guns that we are going to study in the following posts.

Light machine guns are generally designed to use the same ammunition as the rifles carried by the rest of the unit. This feature allows the different soldiers to share ammunition during a battle. For instance, the Browning M1918 uses .30-06 ammunition, the same as the M1903 rifle carried by US soldiers in World War I, the M249 SAW uses the same 5.56x45 mm. ammunition used by M16 rifles etc. Since LMGs are designed for automatic fire, many feature high capacity magazines, such as drum magazines, pan magazines or ammunition belts. However, some models of LMGs are designed to use the same box magazines as the assault rifles carried by the rest of the unit, so that they can share both magazines and ammunition between themselves. Some newer LMGs are designed to use multiple methods of feeding ammunition. For instance, the FN Minimi, the M249 SAW, IMI Negev and the Heckler & Koch MG 43 (now known as the MG4) are designed to use both ammunition belts, as well as box magazines. This allows the machine gunner maximum flexibility in using ammunition and magazines during a battle.

A M249 equipped with an ammunition belt. Click on the image to enlarge. Public domain image.


While the LMG is light enough to be carried by a single soldier and fired from the hip, it is generally fired from the prone position. Because of this, many LMGs have a bipod attached to the front of the barrel, to allow the user to comfortably operate the weapon from the prone position.

In recent times, many LMGs are modifications of an existing assault rifle design. Examples of these include: RPK (Russian LMG design based on the AK-47), Steyr AUG LMG (Austrian rifle based on the Steyr AUG rifle family), INSAS LMG (Indian rifle based on the INSAS rifle family) etc. However, the LMG versions are generally designed with longer and heavier barrels, to sustain automatic fire for longer periods of time without overheating. Some models (such as the Steyr AUG LMG) have quick change barrels to solve the overheating problem. The parts of the action are also designed to be more robust than the assault rifle versions, in order to shoot in full automatic mode for longer periods of time.


An INSAS Light Machine Gun. Click on the image to enlarge.

A Bren gun. Public domain image.

The above image shows a Bren gun Mark I. Note the curved box magazine mounted on top of the rifle and the carrying handle in the middle of the gun, which also doubles as a tool to remove a hot barrel. Later models came with heavier chrome-lined barrels, which reduced the need to interchange barrels. The Bren gun was first adopted in 1938 by the British, produced by various commonwealth countries (UK, Australia, Canada, India) over the years and is still being manufactured currently in India!

The Madsen machine gun also has a long history, being originally manufactured by Denmark in 1902 and still going strong in the hands of Brazilian military police, well into the 21st century! It just goes to show that good designs can last a really long time.,

In our next post, we will study another class of machine guns: the heavy machine gun.


8 comments:

  1. I think you mean HK MG43. The MG34 predates World War 2 and was a Mauser development of a Rheinmetall design.

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    Replies
    1. Yes I did. Nice catch of the typo, I'm fixing the article. Thanks much sir.

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    2. Crap... For some reason, this didn't post. Trying again--This is part one to my reply that starts below.

      I'm going to have to break this down in at least three parts, maybe four, in order to fit it into the character limits of this site, so please be patient with me.

      I fear that I find that this post is inadequate, at best, particularly as it refers to US military general usage and doctrinal definition. I'll try to provide some clarity based on my experience and military experience which covers about 25 years of service encompassing usage and training with these weapons.

      When you set out to define your terms in regards to classification of machine guns, you've got to remember that every military organization has a different history and a different outlook on the whole thing than what you'd might expect from general usage in the English language. The UK/Commonwealth terminology is not precisely analogous to the US, and when you start trying to translate from other languages and doctrinal structures, it gets murky as all hell. You think you're saying one thing, because on the surface it looks like a direct translation from German, and it actually turns out that they don't use the term the way we would. As well, there are even distinct differences between branches of service, particularly in the US military.

      One thing you've missed entirely here is the concept of the Automatic Rifle, which is a distinct class from the Light Machine Gun (for which I'll abbreviate from here with AR and LMG). An AR is a weapon class derived from French tactical thought going back to pre-WWI and probably midway during the war, which was that you were going to stand your infantry up and move forward, firing at the enemy. Obviously, doing this against machine guns was utterly foolish, but they saw no way forward besides this, and the Automatic Rifle was intended to be able to provide a greater volume of fire during this movement--Thus, the term "Marching Fire". This is where the French came up with the requirement for the Chauchat, and how it was used. The idea was that a moving crew-served weapon was a bad idea, and that diffusing the firepower across the infantry section in one-man weapons which were moving was a more viable concept than having two or three men clustered around a crew-served weapon. When the US came into the war, the French trained many of them, and a lot of the techniques were passed on. What the French termed "Marching Fire" the US brought into service as "Walking Fire", and retained that concept well into the WWII era and a little past it. An AR-class weapon was crucial to working with this concept, and the BAR derives from an attempt to create a suitable weapon for this tactical approach. Arguably, I would have to contend that the entire idea is/was insane on the face of it, but I'm working from a standpoint of roughly 75-100 years more experience with fighting this sort of war. Looking at the situation from the aspect of what won wars in the 19th Century, and what was known? Hard to say... Maybe the idea wouldn't have looked quite as crazed.

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    3. You can edit all you want, but you're still going to miss stuff until you actually post it...

      The second sentence in the second paragraph should read "training and military experience", not "experience and military experience".

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  2. Part two:

    This has influenced terminology and definitions in US doctrine down to the present day: We still differentiate between the two roles, and the M249 can be either an AR or an LMG, dependent upon what accessories it is issued with, and what role it is meant to fill in the MTOE. Issued the M249 with no tripod or T&E mechanism? It's an AR, and intended to be operated by one man. Given a tripod and T&E? You're going to have a dedicated Assistant Gunner in the MTOE, and the weapon is intended to be used in the LMG role, for sustained fires. Huge difference, tactically, and one I'll provide more details on in a bit.

    So, the AR is a distinct class of weapon deriving from a tactical concept that was practically the obverse of the one that led to the creation of the LMG. Major differences, doctrinally? One-man vs. crew served operation, and the intent for the weapon to be fired on the move, rather than leapfrogged from position to position.

    An AR is not an LMG, period. An LMG can be crew-served, generally possesses itself of a changeable barrel, in order to provide sustained fires, and can be mounted on a tripod for repeatable, precisely directed fires. None of these features is common to an AR, and weapons that feature them fill a distinctly different tactical role than the AR. A BAR is an AR, right there in the name. A BREN is not an AR, although it can be fitted into that role quite nicely. On the other hand, a BAR cannot serve as an LMG, in that it is not amenable to being served by a crew, cannot be mounted on a tripod, and does not have a changeable barrel or a cooling system adequate to allow the delivery of sustained fires. These are key features, and directly impact how the weapon can and will be used tactically.

    Bottom line up front is that there's a whole lot of information that you've either left out here, or that is flat-out wrong, per US military doctrinal and historic usages. International usages? Man, even I start getting confused, because what the Germans term things these days is totally polluted through exposure to US and other NATO members usages. Pre-WWII German doctrinal terminology is not the same as post-WWII, but it is similar enough to confuse the living hell out of anyone who isn't familiar with the terminology of both periods.

    This extends to even the US: Once upon a time, a Heavy Machine Gun was a water-cooled weapon, and Medium Machine Gun was the same gun, but air-cooled. Inclusion of the heavier caliber M2HB as a "Heavy Machine Gun" is something you don't really start to see until late in the Cold War. And, despite its use in the role, the M60 GPMG was never termed or issued as an AR, though it did arguably fill the role in real terms, tactically speaking. I'm still not sure that it is completely correct to term the M2HB an HMG, to be quite honest, although it is commonly referred to as such.

    These issues are quite important, outside the Trivial Pursuit aspects. When you're discussing the tactical roles you can fill with the guns, for example? An M249 in the AR role, or a BAR cannot do the things you can do with either an M249 or a BREN in the LMG role.

    An example? Let us examine planning a defense of a position, where we can dig in and plan for fires delivered along pre-planned lines with the M249 in the LMG role, or a BREN. You cannot do that sort of thing as efficiently with a BAR or an M249 in the AR role, because you don't have a tripod and T&E mechanism in order to provide repeatable fires along pre-planned lines, nor can you sustain the same rates of fire, given that you can't change the barrels in the BAR, and that the M249 in the AR role is generally found with only one barrel and no spares on the MTOE. So, when you're planning a defense? An AR is really just a slightly better individual weapon, while an LMG is a key supporting weapon, one that your defense is going to be based around.

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  3. Part three:

    Additionally, the use of these "extra accessory items" can be quite effective outside the defensive roles: It's nearly impossible to safely deliver indirect supporting fires overhead of advancing infantry without a tripod in the attack. You can do it, but I don't want to be the guy out in front while the gunners are relying on aiming stakes and so forth to fire over my head. Same-same with conducting pre-planned withdrawals or counter-attacks: Provision of a tripod and pre-plotted range cards for specific positions that you've previously reconned allows the use of these weapons to rapidly move from position to position and safely provide supporting fires, something you have a hell of a hard time doing with an AR.

    There are clear distinctions and details that need to be addressed, when discussing this stuff, much of which is missing from this posting.
    This has influenced terminology and definitions in US doctrine down to the present day: We still differentiate between the two roles, and the M249 can be either an AR or an LMG, dependent upon what accessories it is issued with, and what role it is meant to fill in the MTOE. Issued the M249 with no tripod or T&E mechanism? It's an AR, and intended to be operated by one man. Given a tripod and T&E? You're going to have a dedicated Assistant Gunner in the MTOE, and the weapon is intended to be used in the LMG role, for sustained fires. Huge difference, tactically, and one I'll provide more details on in a bit.

    So, the AR is a distinct class of weapon deriving from a tactical concept that was practically the obverse of the one that led to the creation of the LMG. Major differences, doctrinally? One-man vs. crew served operation, and the intent for the weapon to be fired on the move, rather than leapfrogged from position to position.

    An AR is not an LMG, period. An LMG can be crew-served, generally possesses itself of a changeable barrel, in order to provide sustained fires, and can be mounted on a tripod for repeatable, precisely directed fires. None of these features is common to an AR, and weapons that feature them fill a distinctly different tactical role than the AR. A BAR is an AR, right there in the name. A BREN is not an AR, although it can be fitted into that role quite nicely. On the other hand, a BAR cannot serve as an LMG, in that it is not amenable to being served by a crew, cannot be mounted on a tripod, and does not have a changeable barrel or a cooling system adequate to allow the delivery of sustained fires. These are key features, and directly impact how the weapon can and will be used tactically.

    Bottom line up front is that there's a whole lot of information that you've either left out here, or that is flat-out wrong, per US military doctrinal and historic usages. International usages? Man, even I start getting confused, because what the Germans term things these days is totally polluted through exposure to US and other NATO members usages. Pre-WWII German doctrinal terminology is not the same as post-WWII, but it is similar enough to confuse the living hell out of anyone who isn't familiar with the terminology of both periods.

    This extends to even the US: Once upon a time, a Heavy Machine Gun was a water-cooled weapon, and Medium Machine Gun was the same gun, but air-cooled. Inclusion of the heavier caliber M2HB as a "Heavy Machine Gun" is something you don't really start to see until late in the Cold War. And, despite its use in the role, the M60 GPMG was never termed or issued as an AR, though it did arguably fill the role in real terms, tactically speaking. I'm still not sure that it is completely correct to term the M2HB an HMG, to be quite honest, although it is commonly referred to as such.

    These issues are quite important, outside the Trivial Pursuit aspects. When you're discussing the tactical roles you can fill with the guns, for example? An M249 in the AR role, or a BAR cannot do the things you can do with either an M249 or a BREN in the LMG role.

    ReplyDelete
  4. Part four:

    An example? Let us examine planning a defense of a position, where we can dig in and plan for fires delivered along pre-planned lines with the M249 in the LMG role, or a BREN. You cannot do that sort of thing as efficiently with a BAR or an M249 in the AR role, because you don't have a tripod and T&E mechanism in order to provide repeatable fires along pre-planned lines, nor can you sustain the same rates of fire, given that you can't change the barrels in the BAR, and that the M249 in the AR role is generally found with only one barrel and no spares on the MTOE. So, when you're planning a defense? An AR is really just a slightly better individual weapon, while an LMG is a key supporting weapon, one that your defense is going to be based around.

    Additionally, the use of these "extra accessory items" can be quite effective outside the defensive roles: It's nearly impossible to safely deliver indirect supporting fires overhead of advancing infantry without a tripod in the attack. You can do it, but I don't want to be the guy out in front while the gunners are relying on aiming stakes and so forth to fire over my head. Same-same with conducting pre-planned withdrawals or counter-attacks: Provision of a tripod and pre-plotted range cards for specific positions that you've previously reconned allows the use of these weapons to rapidly move from position to position and safely provide supporting fires, something you have a hell of a hard time doing with an AR.

    There are clear distinctions and details that need to be addressed, when discussing this stuff, much of which is missing from this posting.

    ReplyDelete
    Replies
    1. Thank you for your comments takirks. Some of the points you brought up have actually been covered by other posts in this series and a few are being worked on. Once again, thank you for your valuable comments and thank you for your service as well.

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