Hi guys, thanks for tuning in to another video on ForgottenWeapons.com. I'm Ian McCollum and today we're gonna discuss machine gun terminology. There are a lot of acronyms out there, a lot of three-letter acronyms in particular, We've got LMGs and MMGs and HMGs and SAWs and LSWs and GPMGs – what are all of these things? Well, we're gonna go through one at a time and discuss what they are and what they were used for and, in some cases, what they have turned into. Now, we'll start with the heavy machine gun, the HMG, because this is the first machine gun to really see major combat use – leaving out the ones that were all manually operated. The primary essential characteristics of the heavy machine gun, in the original sense, and I say original because "heavy machine gun" today has a different definition than "heavy machine gun" did in the 1890s when these things first appeared on the modern battlefield. Originally a heavy machine gun was a machine gun designed primarily for a high volume of sustained fire. These were fed by belts, they were typically water cooled, but if not water cooled they had very serious design characteristics to allow for continuous fire for long periods of time. So if they weren't water cooled they typically had very heavy barrels to absorb a lot of heat. Now these guns are responsible for a lot of the image we have of World War 1. When I say that they were designed primarily for sustained fire, that was at the expense of portability. So with these early heavy machine guns like the Vickers and the Maxim and the Hotchkiss 1914, what you have are guns that can only be fired from their mounts (or only effectively fired from their mounts) and when you combine the gun and the mount, you're looking at as much as 100 pounds or more of weight. This is the sort of thing that doesn't move quickly – it often doesn't move at all. What you would do is build a fortified position and place a machine gun in it, and that was the intent. Over time did people realize, we need to be able to move these things a little bit more. After we got out of the conditions of static trench warfare in World War 1 into a more mobile type of warfare like World War 2, the requirements changed a bit, and heavy machine guns sort of morphed into the medium machine gun. The American Browning 1919A4 is a classic example of a medium machine gun. Another good example would be the Soviet SG-43, the Goryunov machine gun. These are intended to provide the same basic role as the heavy machine gun: sustained firepower. But they're giving up a little bit of their real sustained capability in exchange for having a little bit better mobility. So the Russians, for example, have the 1910 Maxim, and they designed the SG-43 Goryunov to take over some of that role. These medium machine guns are going to be distinctive for firing full power rifle cartridges, in this case .30-06, they are going to be belt-fed to allow maximum firepower, typically 250-round belts, they are generally air cooled, because the water-cooled guns, while they offered a little bit better heat reduction and a little bit longer firepower capability, it added a lot of weight, and you could simplify the manufacture and the operation and the weight by getting rid of the whole water cooling system. And so you'll find guns like the SG-43 and the 1919 are air cooled. These don't have quick-change barrels either, they just have very heavy barrels to absorb as much heat as possible before not being able to fire any longer. While these guns are a little bit lighter, they're still designed to be fired from a fixed position off of a tripod only, and medium machine guns don't have bipods. That's one of the other key characteristics that differentiates them from some of the other guns that were out there. So, speaking of which, if we go back to the origins of machine guns with the heavies, because those guns were so heavy, there is an effort to also have something that could be a lot more mobile. The two counterparts to the heavy machine gun where the automatic rifle and the light machine gun, and the light machine gun was invented first, but we're gonna start by talking about the automatic rifle because it shows up, and then it pretty quickly goes away. There were originally two quintessential automatic rifles, and they were the US M1918 BAR and the French M1915 CSRG Chauchat. They were both designed – in fact what they really have in common is they were designed to be fired from the hip or from the shoulder, and also perhaps from a bipod, but the bipod's not really an essential element of the automatic rifle. The original design intent with these guns was to provide a capability for walking fire, where troops could lay down a continuous field of fire while moving from their trench to the enemy trench or enemy position. Now this didn't turn out to be a very successful tactic, and it was pretty quickly abandoned, but the automatic rifles, they did survive the abandonment of that original tactic. And what the automatic rifles ended up really giving to a squad, or giving to their firer, was the capability to have really overwhelming firepower for a short period of time. So the key essential ingredients to an automatic rifle are going to be: having a relatively limited magazine capacity, these aren't gonna be fed by particularly large magazines or belts or anything like that; they're capable, in fact designed to be fired from the shoulder or from the hip; they don't necessarily have to have a bipod, although that isn't ruled out; and they aren't designed to have very much sustained firepower at all. They're really a weapon to be used in an imminent assault and then allowed to cool down, so not something that you set up in a position and, say, use as a defensive gun to hold back waves of enemy troops. Now, they always get put into that role, which is part of the reason the automatic rifle has mostly disappeared from use. In the Korean War, the US troops tended to put the 1918A2 BAR into that role, which led to burned out barrels because it doesn't have any quick change barrel mechanism. Again, automatic rifles are not designed for sustained firepower, so you won't find quick-change barrels, you won't find very heavy barrels, you won't find any of the usual design elements for increasing the sustained rate of fire of a gun. In World War 1, the French Chauchat was kind of put into the same role. While it was primarily used to assault an enemy position, it then, once a position was captured, the Chauchat was the one thing that was immediately available to set up as a temporary defensive machine gun while guns like Maxims or Hotchkiss or Vickers guns were brought in to support the newly captured territory. What's interesting about the automatic rifle is that it has actually, to some extent, made a bit of a comeback in the US Marine Corps' M27 IAR with, interestingly, basically the same design idea. The IAR replaced the SAW, and we'll touch on SAWs in a little while, replaced the saw in Marine Corps use because they decided that accuracy was more important than volume of fire for suppression, and they wanted to have a lighter weapon. See if this sounds familiar. It's capable of being fired from the shoulder, Doesn't have a super heavy-duty barrel or a quick-change barrel, or a belt feed, or anything to really increase its durability of fire, but it does allow for large volumes of fire for short periods of time. Now, the US Marine Corps is also really utilizing the accuracy of those guns as part of its design philosophy, which didn't really apply to the early automatic rifles, But still it's interesting to see that concept make a comeback post-2000. Anyway, the other counterpart to the automatic rifle, which quickly took over its role, is the light machine gun. This was an attempt to increase the durability of the guns just a little bit at the sacrifice of just a little bit of portability, but to make them much more practical for general use on the battlefield. The light machine gun really got its start in World War 1, with the Lewis gun and the Madsen light machine gun like this, and its heyday would run basically until the end of World War 2, when these would largely be phased out of service, or the process would begin of phasing them out of universal military service. So, the critical elements of a light machine gun are going to be: firing from a box magazine, not a belt. This is an instance where the portability is more important than the volume of fire. They're going to fire full power rifle cartridges, so in this case, .30-06 or 8mm Mauser, and they're going to be designed to fire from bipods. You can fire a light machine gun from the hip or from the shoulder, but it's not really the design intent, it just happens to be that, because of the way the design is put together, you're not precluded from doing that, but the effective way to fire these guns is from the bipod. What was found was that firing from a bipod is really a much more practical use of automatic fire, especially with full power rifle cartridges. Firing this sort of thing from the hip and walking fire just wasn't all that useful, firing it from the shoulder tended to be difficult to control and not as useful, the bipod is what really brought the light machine gun into its heyday. So if we compare these to the heavy and medium machine guns, what we'll see is that you have the option of emphasizing portability or emphasizing firepower. The medium and heavy guns emphasize firepower, the light machine guns and automatic rifles emphasize portability. The Madsen is a good example of this, the Madsen is in fact the first practical and fielded example of the light machine gun, but you'll see a whole slew of others during the time period in the 20s and 30s and World War 2. The Japanese Nambu 96 and 99 light machine guns, the British Bren gun, the Czech ZB-26, the French Châtellerault 24/29, all of these things are really quintessential light machine guns, and you'll know: they're all magazine fed, rifle caliber, and they don't have any particular features to really increase their rate of fire, their rate of sustained fire. Some of them will have quick change barrels, some do not. The quick change barrel is there to try and allow the gun to be pushed out of its envelope towards that of a medium or heavy gun, and because you generally don't lose anything by having a quick-change barrel, it's not that complicated to add to the gun and so it's an easy addition to make without really changing the true nature of the light machine gun. Now, these would be phased out basically starting at the end of World War 2, as would the medium and heavy machine guns, because all of these started to come together into a single thing called a general purpose machine gun. The Danes were the first to actually kind of codify the idea of a general purpose light machine gun, but the Germans were the first to really put it into serious service with the MG 34. And the idea here is to have a gun that can be used for, as the name implies, anything you would need to do with a machine gun, to consolidate all the different types of gun into a single design. That makes it logistically a lot easier to manufacture, to supply, to train, etc. So the four main roles that you're trying to fill are going to be vehicle mounted machine guns, aircraft mounted machine guns and anti-aircraft machine guns, which have basically the same sort of defining characteristics, light machine guns, and heavy machine guns. The way this was done by the GPMG concept was to have a gun with a fairly high rate of fire, a high rate of fire is essential to aircraft and anti-aircraft use, because you're firing at fast-moving targets and need to make the most use of whatever opportunity you have on target, and then to have the guns equipped with both bipods and sophisticated tripod mounts. The idea being, you make the gun just light enough that it can be carried and fired by a single individual, from basically a permanently mounted bipod, which allows it to be used like a light machine gun, although they're generally heavier than true light machine guns. This is a compromise solution, after all. And at the same time, you have a tripod mount (in the German case, the Lafette mount) That allows very fine-tuned adjustment of windage and elevation, and typically also has a recoil absorbing mechanism built into it to help increase the long-range accuracy of the gun so it's not bouncing the tripod around. The idea there is to be able to take a gun that's still capable of being used as a portable light gun, but bolt it onto this tripod and be able to push it into service as a heavy machine gun for sustained fire. So what you'll find with these guns: GPMGs are always going to be belt fed because they do need that belt, that long belt feed capability to truly have sustained fire, as well as to be capable of being used in vehicles or aircraft, where you don't want to have to be accessing the gun to change a magazine every 20 or 30 rounds. They will fire full power rifle cartridges, which is essential to their role as a heavy machine gun, for sustained fire, at long ranges, and potentially at harder targets than just men in the open, and they will typically have some sort of a pretty effective cooling mechanism, and usually this takes the form of a quick-change barrel, could also be a heavy, or a fluted barrel, but you'll see with guns like the MG 34 and the MG 42, they were specifically designed to have very easy quick-change barrels, and they were they were carried and issued with several spare barrels. And so typically, doctrine on one of these guns would be when it's being used from the Lafette mount in a supporting or heavy role, every time the belt has changed, so every 200 or 250 rounds, the barrel would also be changed, and if you had three barrels rotating through like this, it allowed the barrels to cool sufficiently that you could basically fire continuously. Now, not dumping belts continuously, but as fast and as rapidly as is typically necessary in a combat environment. Now this concept turned out to be really successful and really popular and after World War 2, pretty much every country started looking at it and deciding to copy it, and probably the best example of copyin that concept is the Soviet PK and PKM machine gun. This took exactly the same concept and did it, frankly, better than the Germans did with the MG42. It is a gun that is relatively lightweight, the PKM is actually in a weight class similar to a lot of the World War 2 light machine guns, it has a built in integral bipod and it also has a lightweight but very effective tripod mount, and a very easy quick-change barrel. And it really can suffice in all of this whole arc of roles from light to support machine gun. The PK and PKM are used by a bunch of militaries today as their general purpose machine gun, it's still totally capable in that role. On the more western side of things you'll see the M240, FN's 240, being used as a general purpose machine gun, you see it mounted on vehicles as well. It does have a bipod, the 240 is a substantially heavier gun than the PKM, closer to something like an MG 42 was. In fact you see the MG 42 basically still in use by some militaries today, just rechambered for 7.62 NATO and slightly modernized. This is the primary machine gun that still exists in today's modern military environment. However, it's not the only machine gun that's still being used. We also have, today, what are called squad automatic weapons, or if you're British you call them a light support weapon. LSW isn't really a general term. It just happens to be the designation given to the L86, which is the UK's adapted version of this sort of gun, and the reason that these exist is because a general purpose machine gun, while it can be pushed into the role of a light machine gun, and often very successfully, it's still a bit of a challenge to have a unit of soldiers, most of whom have rifles using one caliber, one cartridge, to also have a guy carrying a heavier gun that uses both a different feeding mechanism and an entirely different cartridge. So, if you were gonna have a squad of guys and one of them has a 240 or a PKM, you have to have a supply of, presumably, 5.56, their standard ammunition, as well as a supply of 7.62 NATO for the GPMG. It's a lot simpler if you can offer a full full auto capability to the squad without requiring them to carry different ammunition, and that's the role of the SAW, the squad automatic weapon. So, the RPK, the RPK-74, the M249, the FN Minimi, the British LSW, these are all examples of light support weapons or SAWs, squad automatic weapons. And the distinguishing characteristics of these are that they're going to use whatever cartridge the actual riflemen use, which today means an intermediate cartridge – 5.56, 5.45, or 7.62x39. They're going to be typically magazine fed, but not always. I think it's interesting to point out that the most common belt fed SAW is the US SAW, the FN Minimi, however, those guns are designed to also be capable of feeding from standard M16 magazines. Now they don't necessarily do it very reliably, but I think it really highlights the importance of that characteristic that the gun is designed primarily as a belt fed, but does have the option of using the same magazine that the standard squad soldier is going to be carrying. That highlights the importance of the logistical similarity and the additional portability you get. You don't have to have guys dragging around a whole bunch of different ammunition for the machine gun. So today we have primarily GPMGs and SAWs having taken over the roles that were basically originally fulfilled by heavy machine guns and light machine guns It's interesting how the two different specialties have modernized, and what we see is that the guns in general have gotten lighter, and obviously have gotten much more reliable and more combat effective, but we still can't quite combine both roles into a single gun perfectly. We have better compromises today, but not so good that we don't still have slightly specialized different types of gun for the different purposes. So there's one other type of machine gun that we need to touch on here, and that's the heavy machine gun. Not the same heavy machine gun we talked about at the beginning, but rather the modern understanding of the heavy machine gun. And where a World War 1 heavy machine gun is typically .30 caliber and water cooled, a modern heavy machine gun is air cooled and .50 caliber, somewhere between .50 caliber, which is 12.7mm, and 20mm. Once you hit 20mm you're in the realm of what's considered a light weapon, and a 20mm gun is considered a cannon, it's no longer a machine gun. So for that space between 12.7 and 20mm, you have guns that are designed for attacking things like light vehicles and infrastructure, shooting through building walls, shooting things like delicate installations, radar, fuel tanks, that sort of thing, something that needs a larger, more powerful bullet than a .30 caliber, than a GPMG would be capable of delivering. So the heavy machine gun in this form originated shortly after World War 1. In fact, its origins were being designed to be an anti-tank weapon. .50 caliber Browning, in 1919, was capable of basically taking out any armored vehicle then in existence. But tanks, tank armor grew pretty quickly and by the time there was another real war, .50 caliber Browning ammunition wasn't really an effective anti-tank weapon, or wouldn't be for very long. So these guns were pushed into anti-aircraft use. By the end of the Korean War, aircraft were simply moving too fast for a machine gun to really be a viable anti-aircraft weapon, so they're kind of pushed out of that role and they remain today as anti-materiel and anti-light vehicle sorts of guns. You'll see them primarily mounted on vehicles or mounted in fixed positions, kind of like the heavy machine guns from World War 1, so we have a situation where the nomenclature has stayed the same, but what it's really describing has has changed fairly fundamentally, from a gun that's heavy to a gun that fires a heavy cartridge. Now of course, not quite everything really is going to fit neatly into this puzzle of terminology. There're always going to be some outliers because people don't design guns to fit these standard terms, they design guns to do specific jobs, and then we take this whole field of guns and we try and kind of encapsulate them into various names, various labels. So we're always going to be left with some things like this, that just don't really fit any of our definitions. This is a 1919A6, this is the Israeli variant of the gun, or Israeli take on how to make a 1919A6. This comes about from the US government having the 1919A4, which didn't have a buttstock, didn't have a bipod, had to be fired from its own tripod, looking at this gun and going "well, jeez, the Germans have these machine guns that they can just pick up off the tripod, flip down a bipod, and run around with, and they're way more mobile and boy wouldn't it be nice if we could do that," so they basically kludged on a bipod and a shoulder stock, the shoulder stock is literally held in place by a giant thumb screw it is the definition of, like, the Acme light machine gun kit, and what you end up with is a gun that technically works. You can pick this thing up, run to a position without a tripod, throw it down on the bipod, get behind it with the shoulder stock, and use it like a light machine gun, but boy, it's a really heavy light machine gun. So what does this technically fall into? Well, I would say it's a light machine gun, it's just not a very good one. Another example along these very same lines would be the German MG 08/15, This was kind of the same sort of thing, it was, "Wow, boy, those British have some, uh... you know, the French have this Chauchat and the British have this, uh, Lewis gun, and it'd be really nice if we had a machine gun that someone could just pick up and move with, so let's take the Maxim and let's try and turn it into a light machine gun." This thing is a little too heavy, and it's belt fed, which is awkward in a light machine gun. The 08/15 was even worse, it was a little too heavy and belt fed, and it was still water cooled, and they were trying to run around with it. I mean that thing was like 45 pounds. But hey they put a pistol grip on it and a bipod, so it must be a light machine gun, right? Well, sort of. These are examples where our terminology isn't really well matched to the guns, but I would argue it's because the guns really weren't well matched to their roles. So I'm sure in the comments folks will come up with some other examples of things that don't really quite fit these parameters. It's always interesting to take those and and consider, what would they fit into? Anyway, hopefully you guys enjoyed this video. Hopefully you learned something today about the various types of machine guns out there, and why they fall into the different categories that they do, how they were used and what's still being used today. If you do enjoy this sort of thing please do consider checking out my Patreon page, but more importantly, thank you very much for watching.
I was at my parents this holiday and they were watching something called forged in fire and I fucking swear this is the guy that was on there that they kept telling to talk about getting hit by lightning. I cant prove it