Evolution in Action: The Parabolic Arc of the Stamped Steel Submachine Gun

By Will Dabbs, MD

The “Iron Age” is a term used to describe an archaeological era.

Depending upon whom you ask, it began between 1,200 and 600 BC. This epoch also typically corresponds with the period of time wherein writing took on more importance than just wandering around trying to stay alive. As a result, most historians use the Iron Age to demarcate the transition from prehistory to history.

Iron liquefies at 1,538 deg C so the limiting factor in our working with iron early on was the capacity to get it really, really hot. Man has actually been making stuff out of iron harvested from meteors since around 3,200 BC. However, it was not until we developed the capacity to smelt iron ore and subsequently regulate the amount of carbon in it that we really got any mileage out of this most common of metals.

Nowadays we make everything out of the stuff. Knives, tanks, cars, fingernail clippers, tall buildings and aircraft carriers all begin as elemental iron. When properly alloyed into steel it is arguably the ideal building material. Before you fret about perhaps running short, appreciate that iron is the fourth most common element in the earth’s crust. We won’t be running low any time soon.

In more recent years our capacity to mill and manipulate steel transformed warfare. In 1760, Britain saw the dawn of the Industrial Age. The steady progression in our capacity for mechanization eventually spawned World War I, the first truly global war fought on an industrial scale. The subsequent carnage was without human precedent.
Getting Out of the Trenches

This first War to End All Wars saw the introduction of the tank, the combat submarine and poison gas and massed indirect fires to a battlefield that was just beginning to resemble the sorts we squabble over today. The inability of the military leadership of the day to adapt previous era’s tactics to these modern weapons is what resulted in the bloody stalemate that so characterized that horrible time. In the case of small arms, however, the state of the art advanced rapidly.

Hugo Schmeisser, Theodor Bergmann and John Taliaferro Thompson all produced tools to get their respective soldiers out of the trenches and back on the move. Schmeisser and Bergmann’s MP18 used the 32-round snail drum of the P08 Lange Pistole Artillery Luger and provided German Storm Troops with markedly more individual combat power than had previously been the case. General Thompson’s eponymous gun was just a shade too late to see combat in 1918. In both cases, these early efforts at the submachine gun were laboriously milled out of big chunks of steel. To fight the next war on an even grander scale would require something we could churn out a little bit faster.

The MP40

The MP40 was itself an evolutionary offshoot of that original MP18. The MP18 became the similar but improved MP28 which morphed into the little-known MP36, of which only a copy or two ever saw the light of day. The subsequent MP38, however, began to take on a more familiar form.

The MP38 was built around a milled steel tubular receiver that sported longitudinal lightening cuts along its length. At a glance the MP38 looked very similar to the subsequent MP40, the definitive German World War II subgun. In addition to the longitudinal grooves in the receiver, all MP38’s included a dime-sized hole punched in the center of their magazine wells. MP40 magwells came both smooth and ribbed, but none of them carried this distinctive hole.

The MP40 was an interesting hybrid. The recoil system telescoped back into itself in the manner of those pressed metal collapsible camping cups we all used to have in Boy Scouts an age ago. This feature was undoubtedly superfluous but offered an extraordinarily smooth cycle as the gun fired. The rear sight was flip adjustable out to 200 meters, and the stamped steel underfolding stock was undeniably revolutionary. The synthetic forearm was formed from an early polymer material called Bakelite, a thermosetting phenol formaldehyde resin named after its founder Leo Baekeland. Production of these components was undertaken within a device called a Bakelizer. Aside from the bolt and barrel, everything else that could be made of pressed steel stampings was made from pressed steel stampings.

The capacity to press steel is still the fastest way to produce robust steel machine parts en masse. The dies used to produce these parts are massive, expensive and tedious to build from scratch. However, once these devices are milled, set up and calibrated, such an industrial press can produce vast quantities of identical parts quickly, easily and cheaply using moderately skilled labor. Guns would never be the same.

Even at the very end of production when the situation grew utterly dire for the Third Reich, those persistent Germans still maintained their odd sense of mechanical superiority. They stamped serial numbers on every component big enough to accept it and threaded the barrels of their MP40’s for blank adapters that were undoubtedly never to be used. While the Nazis were busy serializing everything larger than a trigger pin we were pushing out M1 Carbines to the tune of 65,000 per day. Though they did produce roughly 1 million MP40 submachine guns before the MP44 Sturmgewehr supplanted the design, this classic German burp gun had some manufacturing corners that could have been safely cut.

Meanwhile, On the Other Side of the Pond...

We Americans found ourselves thrust into a come-as-you-are party at the beginning of World War II, so we threw ourselves into building Thompson submachine guns despite the fact that the design was already hopelessly obsolete.

Even in the product-improved M1 and M1A1 models that were supposed to be easier to make, these massive guns were manually cut from big chunks of ordnance steel. Though we did eventually produce 1.5 million of General Thompson’s guns, the Ordnance Department set out in 1941 to divine a replacement.

The original M3 Grease Gun carried the designation T20, and it was accepted for production in December of 1943. Guide Lamp produced a bit north of 600,000 copies before the end of the war. Rumor has it the gun’s baptism by fire in the European Theater was actually during the D-day invasion.

The M3 receiver was formed out of two half-sheet steel shells that were created via industrial pressing. These two shells were then welded together to form the gun. The bolt rode on a pair of guide rods such that the specific details of the inside of the receiver were not critical to the gun’s reliable functioning. Early M3s used a ratcheting handle that tended to fail under hard use. In December of 1944 the simplified M3A1 was introduced that dispensed with the ratcheting handle in favor of a simple finger divot in the bolt.

The Grease Gun was intended to be disposable in combat, and the supply system did not stock spare parts as a result. A field expedient fix for the broken ratchet system was to mill a longitudinal slot down the right top aspect of the receiver to accommodate a simple post-style charging handle in the manner of the British Sten. Several of these field-modified M3 guns are in the collection of the National Museum of Military History in Luxembourg. The M3A1 did not see action in World War II but fought heavily in both Korea and Vietnam. I saw tankers still carrying original M3A1 Grease Guns when I was on active duty in the 1990s.

The Modern Treatment

The German MP5 began life as the fourth iteration of the G3 battle rifle.

The G3 was an evolutionary development of the Spanish CETME that itself spawned from the wartime German StG-45. Originally christened the HK54, this roller-locked 9mm submachine gun followed variations chambered in 7.62x51mm, the Combloc 7.62x39mm M43 round and 5.56x45mm NATO. German Federal Police units adopted the gun in 1966.

The MP5 was an interesting hybrid. Designed to maximize the use of industrial stamping so as to be easily mass-produced, the MP5 design is also long on elegance. The complex roller-delayed locking system had its genesis in the German belt-fed MG42 machine gun and, when properly executed, is reliable, strong and accurate.

The MP5 was subsequently produced both under license and not in more than 100 variations in at least a dozen countries. Though other submachine guns have been more widely produced, the argument could be made that none has been as successful. The MP5 remains in production in several countries today.

Turning Ammo into Noise

The MP40 is long, heavy and sedate. Its front-heavy nature combined with the minimal recoil impulse of the 9mm Parabellum round conspire to make the gun imminently controllable. The telescoping recoil system keeps the gun silky smooth. Though there is no provision for semiautomatic fire, an attentive trigger finger can easily get off singles and doubles.

The M3A1 Grease Gun reflects the ethos of the country that made it. Big, heavy and as robust as a tire iron, the Greaser is a blunt instrument. Despite the simplicity of its execution, however, the slow rate of fire and overbuilt nature of the gun make it utterly effective at appropriately close ranges. The argument could be made that little would clear a room better even today.

The MP5 runs markedly faster than our other two contestants, and the guts of the thing more resemble a computer printer than a farm implement. The impeccable nature of the design means that the MP5 produces a prodigious volume of controllable short-range automatic fire that, in the hands of a trained operator, can be remarkably precise. For its intended counter-terrorist mission this half-century-old subgun remains a fearsomely effective tool.

Our MP40 and M3A1 are expensive collectibles. The MP5 we used for our evaluation is actually built from a new-production Z-5RS from Zenith Arms. Built on licensed equipment in Turkey and sporting a true two-push pin lower, the Zenith Z-5 is the closest thing to a factory MP5 available on the civilian gun market today.


These three-stamped steel submachine guns are reflections of the personalities of the nations that birthed them combined with the exigencies of their time. The MP40 was revolutionary, the Grease Gun was utilitarian, and the MP5 was elegant. Though they each share a common method of manufacture, each gun is as philosophically different from the other as day is from night.

Men who felt it their right to enslave the planet wielded the MP40. The Grease Gun equipped those comparably determined to stop them. The subsequent MP5 became a force for good in the decades-long struggle against the worldwide specter of terrorism. In each of these seminal designs we can see embodied conquest, liberty and security, all stamped into a piece of sheet steel.

Special thanks to www.worldwarsupply.com for the reproduction period gear used in this article. www.zenithfirearms.com.

This article first appeared in Small Arms Review V21N4 (May 2017)
and was posted online on March 17, 2017


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