Originally Posted by traveltoad
That said, John is it possible that the MP18 changed how the machine pistol was used on the battlefield? Not it's designed or plan use/function but its actual use and/or function?
The MP18's claim to fame is that it was the first machine pistol widely used by a real army. Since it was the first machine pistol, it really didn't change machine pistol doctrine in any meaningful way that I know of.
The only reason the MP18 came about at all is because the principles of a practical self-loading rifle were not understood at the time. Imagine you're a weapons designer during the WW1 era.
You see how effective the Maxim machinegun is. It has an almost unreal rate of fire and its power and range from its smokeless rifle cartridges seems almost unreal. It was only a few decades before that soldiers were using single-shot muskets propelled by black powder and taking pot shots at each other from static lines. Now you marvel at how such tactics would be futile. You also marvel at how the Maxim uses the recoil forces of the rifle ammunition to cycle itself, with no power required by the operator. The Maxim is water-cooled, and so seemingly it can fire forever without grenading.
Not only can the Maxim fire lots of shots, but its shots are devastatingly effective. The Maxim stops men in their tracks when the bullets land. It even blows right through men and kills the men behind them. It downs horses decisively, as if they were pigeons. At the beginning of this war, cavalrymen were foolish enough to charge the Maxim on horseback. Of course this doesn't happen any more. Strangely, you don't see any more cavalry on the battlefield either, something that had been present in all human conflict since just after the sticks and stones era.
Even men trying to take cover behind trees are not safe, as the rifle bullets used in the Maxim slice right through the trees. Men in vehicles are not safe either, as the rifle ammunition slices right through these vehicles easily and ventilates the men within. The Maxim has the same effect on men trying to take cover in buildings. In coming years, the opponent will create a heavily armored car called a tank, just to resist the tremendous penetrative power of this weapon and its new ammunition.
You marvel at how the Maxim can be used against targets thousands of yards away as an artillery piece. It's very accurate, even at these long ranges, because its projectiles are propelled through a rifled bore. Its long/thin jacketed bullets are driven at previously unheard-of velocites by the new smokeless propellants. The streamlined shape and high sectional density of the projectiles slice through the air and do not bleed velocity quickly and thus are very effective even after traveling thousands of yards. These design attributes combine to make the Maxim frighteningly effective at these extreme ranges.
That's a very impressive weapon and you're quite naturally impressed. Then you see the Mauser bolt-action rifle, the principle weapon of the soldier at this time. This weapon fires the same modern, smokeless rifle ammunition as the machinegun does and it performs the same magic on its targets from a shot-to-shot perspective. But there is a glaring difference between the Mauser and the Maxim. The Mauser holds only five shots and must be reloaded after those five shots are expended. The Mauser must also be manually operated between each shot. In other words, the power of each cartridge is used only to drive the bullet down the barrel and spin it, drive it through the air, and and then drive it through the target. The power of the burning propellants inside the cartridge is not used in any way to make the Mauser reload and operate itself. This manual reloading can be done very quickly and smoothly by a skilled operator, but the soldiers at large are not skilled operators and it takes them precious time to reload their weapons manually. The rate of fire is slow enough that it's standard at this time to affix a bayonet on the end of the Mauser for some fencing action when the fighting is close and the weapon cannot be reloaded quickly enough.
You naturally compare the Maxim and the Mauser in your mind, and you try to incorporate some of the Maxim's virtues into the Mauser. The Maxim is an area target weapon and the Mauser is a point target weapon, but the Mauser does seem to suffer from a low rate of fire. After all, why would a bayonet even be needed if the rate of fire were sufficient? The Mauser is already powerful and has tremendous range, so nothing needs to be done there. So you naturally try to increase the rate of fire by trying to make the Mauser self-loading.
You examine the toggle short recoil method used on the Maxim and try to make this work on the rifle. In this system, as modified for rifle use, the barrel and bolt are locked together and recoil backward for a short distance when a cartridge ignites. After a short while, the barrel stops while the toggle joint on the bolt is broken and the bolt head continues backward until it bottoms out, then springs forward to strip a round from the Mauser's magazine, then continues forward to lock with the barrel once again, and both assemblies travel forward into battery for the next shot. Sounds fine. but you realize that this system won't really work on the Mauser because the resulting weapon would be too heavy. The powerful rifle cartridge generates such a recoil thrust that the operating components would have to be very large and heavy, making the weapon impractical as a shoulder-fired weapon. This is not a problem on the crew-served and large Maxim but on the Mauser using this system would not be practical.
You study other weapons to look for inspiration. You look at Browning short recoil, which also exists at this time. You face the same problems as on the toggle short recoil. The resulting weapon could work, but it would be far too heavy.
You abandon short recoil and try the simple blowback method of operation, a method that exists at this time because it's the oldest self-loading method. Under this system, a heavy bolt is held stationary by simple inertia and forward spring pressure to resist the rearward thrust of the igniting cartridge. When a cartridge ignites, the bullet is propelled forward at great velocity while the case head and bolt are driven backward. Because the bolt is so much heavier than the projectile, the bolt moves backward at a much slower rate. You quickly realize this won't work either, as the bolt of this blowback weapon would have to weigh 40 lbs. for it to contain smokeless rifle cartridges. Anything lighter than that and the bolt will fling rearward at too high a velocity and during the peak pressure cycle of the cartridge. A 50 lb. rifle wouldn't be too practical either.
So what do you do? You can create a self-loading rifle but you can't seem to create a practical self-loading rifle. You can't do it because you're not quite sure yet how to go about it. All of the existing self-loading methods you've examined won't work.
You rack your brain for ideas. You can't figure out how to make a practical self-loading rifle. But there's clearly a need for a higher rate of fire from the rifle. The current rifle isn't cutting it and your superiors are pressing you for something. Thousands of men are dying every day and the war is severely stalemated. Any edge you can give to the soldier might be enough to break the stalemate. Your superiors are even trying shit like poison gas to try to break the stalemate. You're under tremendous pressure to come up with something to try to solve the problem.
So you do. You can't create a self-loading rifle but self-loading pistols certainly exist at this time and their methods of operation are well understood. But these pistols are weak and are difficult to shoot well. So you come up with the idea of a shoulder-fired, self-loading weapon that fires a pistol cartridge. This weapon is shoulder-fired and thus easier to shoot well. That combined with the weak pistol cartridge chambering make this weapon very easy to shoot well. This weapon is self-loading and thus has the capacity for very high rates of fire. You know in your heart of hearts that a pistol cartridge isn't going to cut it, but perhaps more bullets will make up for the fact that each bullet is tremendously weaker than each rifle bullet. So you make the weapon fully automatic, even though this weapon is a point target weapon and not an area target weapon. If one bullet can't get the job done, then perhaps several bullets landing in quick succession on the target may do it. It's certainly worth a try, for the current bolt-action rifle isn't cutting it and the idea of a self-loading rifle seems like an impossible dream right now. Things are desperate and it's worth a try. So you run with the idea and create the MP18.
This gross oversimplification is basically how the MP18 came about. It was an attempt to increase the soldier's rate of fire in a time when rifles were manually operated and weapons designers did not yet understand how to make them self-loading. The machine pistol was never suitable for the job because of its lack of power, and it never supplanted the rifle. At most, the machine pistol supplemented the rifle. However, the machine pistol never supplemented the rifle adequately, the way other personal weapons like the pistol and shotgun did in the past and still do today. From the very beginning, the machine pistol was found wanting and weapons designers immediately searched for other solutions. Once firearms designers figured out how to create practical self-loading rifles, the machine pistol fell by the wayside. And the invention of the assault rifle basically killed the machine pistol.
Originally Posted by traveltoad
Or perhaps the MP18's production methods help shape future manufacturing?
Small arms development comes in many forms, and better methods of production are definitely just as important better methods of operation, better ergonomics, better ballistics, etc. After all, wars are waged on a grand scale and the speed and ease with which a weapon can be produced and fielded are huge concerns on this macro scale.
But there is nothing innovative about the MP18's method of production. I believe the MP18 is machined from forgings, which was typical of its era. Its stock is wood and features the traditional rifle configuration. It's very typical of its time. There's really nothing unique about it.