Do you want to know about type of guns. The key essential ingredients to an automatic rifle are going to be: having a relatively limited magazine capacity, these aren’t going to 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.