The Machinengewehr 42 (MG-42), Hitler’s Buzzsaw
By David Tong
There is little question to this author that German designs played a seminal role in the development of modern military small arms. The examples are numerous.
One of the most lasting examples of this technological foresightedness was the fielding of a new generation of general purpose machine guns (GPMG). The concept was to reduce the size and weight of these crew-served weapons and thus open up their doctrinal use in both the infantry unit, as well as armored vehicle mounting.
Up to this time, most machine guns were truly heavy. Examples such as the American Browning M1917 and M1919 and the British Vickers weighed over 30 pounds before their mounting tripods were fitted and thus were suited primarily as defense weapons, or used as support fire for rifle troops on the advance. They simply weighed too much for the mobility promised by modern mechanized movement, though they served well mounted on vehicles.
Some of this was due to their heavy riveted plate steel construction, but mostly this was due to their “long-recoil” method of operation, where the bolt and barrel recoiled. This was pioneered by John Browning in his seminal sporting shotgun design, the Auto-5 and later used in his M1917 and M1919 machine guns.
In the 1930's, the Germans created the first GPMG, the MG-34. This was the antecedent to all GPMGs manufactured since, in that it incorporated a straight-line stock design, the ability to be fired from a bipod or tripod, used a pistol grip for better control and was much lighter than earlier WWI era designs, due to its short-recoil design. It also offered the capacity to be fired from either disintegrating metal belts or steel drums of more limited capacity.
German infantry tactics were designed around the machine gun, whereas Allied forces used their older machine gun designs largely in fire support or defensive roles that suited their relative lack of mobility. The Germans decided that their new organizational doctrines meant that the use of light, medium and heavy machine guns was too cumbersome and designed one weapon which could be used in all three roles. The rest of the world largely followed suit. However, in the course of the war, it was found that it was too costly to manufacture, being made largely of machined steel, still weighed too much and was labor intensive. In addition, the design proved to be dirt-sensitive. A request was sent to three manufacturers to create a suitable replacement.
Stubgen, Rheinmetall-Borsig and Grossfuss were asked to submit designs. It is interesting to note that the latter, a sheet metal manufacturer of lanterns with the ability to build at high production rates, was the design selected. They had no prior design history in firearms.
The design resembled the earlier MG-34 in general outline for training continuity, but differed in its manner of operation. The ’42 was the first machine gun to use what has become known as the Stecke-lock, after the Mauser engineer who created it from a captured Polish prototype design. Essentially, the multi-piece bolt is locked into a barrel extension via a moving bolt head and striker sleeve, which is in turn locked in battery by a pair of rollers that fit into recesses in the receiver. On recoil, the striker retracts, allowing the roller elements to move inwards. This unlocks the bolt head and recoil commences. This is a very similar system used today in many of the older Heckler and Koch infantry rifles.
One of the well-known features of the MG-42 is its fairly astounding rate of fire. Through the use of various weights of bolt heads, and a barrel quick- change procedure taking between 5-10 seconds, this thing could put out a theoretical maximum of 1,200 rpm in its most commonly fielded form. Due to the German Army's heavy reliance on the new GPMG, nearly all troops were required to carry ammunition belts to support it.
U.S. Army films warned troops of the psychological effects of hearing this weapon, whose muzzle report was so fast that one cannot hear the individual shots being fired. The author has witnessed this first hand, and it does sound like ripping cloth.
German designers and Army brass thought that since enemy combatants were unlikely to show themselves from cover or concealment for more than a few seconds, it was necessary to develop an arm which would be capable of very high rates of fire in short bursts of no more than 250 rounds, in order to increase hit probability. Some folks like to call this, derisively, “spray and pray” tactics. The author would like to leave it to the reader to decide whether the doctrine is sound given the number of Allied troops killed by MG-42s on the beaches at Normandy and elsewhere.
The MG-42 is among the fastest firing, single-barreled machine guns ever produced. Its use of sheet metal and its feed tray mechanism, straight line stock, pistol grip and operational flexibility have continued to influence the GPMG to this day.
Its drawbacks included its voracious appetite for ammo. The MG-42 was only capable of full-auto fire, while the MG-34 was also capable of semi-automatic fire. Due to the organization of the infantry squad in the Wehrmacht, with heavy reliance on the machine gun both offensively and defensively, it became very difficult to produce enough ammunition. In addition, because of the heat generated, barrels wore out faster and gun crews were trained to replace the barrel after every 350 rounds fired in combat to preserve them. Probably some of this was due to the fact that the majority of German infantry carried the ’98 Mauser bolt action rifle. Due to the need to remove the barrel by unlatching the barrel shroud’s right cover, the MG-42 did not lend itself to mounting within armored vehicles’ front glacis plate.
Curiously, the U.S. Army captured examples during the war and actually made efforts to adopt the design to the longer .30-06 round. The General Motors division Saginaw Steering was tasked with the project and it was determined that the design’s locking system might not be capable of handling this cartridge. However, it is said that the real reason was the company did not re-design the feed mechanism well and the project was shelved.
The German Bundeswehr uses a newer version known as the MG-3 built by Rheinmetall, and it operates exactly the same as the WWII MG-42, while chambered in 7.62X51mm NATO and with a reduced rate of fire. The Yugoslavs built an MG-42 clone in the original 8x57mm caliber known as the M53. It was exported to Iraq and was present in both unpleasant episodes in the Sandbox. The Austrian army uses the MG-74, which is nearly identical to the MG-3 with its 850 rpm capability.
Other well-known GPMG's using design elements of the MG-42 include the U.S. M60, which uses sheet metal comstruction and copied the MG-42 feed tray design. The Belgian FN-MAG-58 copied the trigger group design. The MAG-58 became the later M240B, now used by U.S. forces.
I have fired an MG-42 at the Albany Rifle and Pistol Club’s annual May machine gun shoot. The ominous feeling it generated, as well as its relative accuracy, increased my respect for the courage of soldiers who had to fight against troops armed with MG-42's. It is a most frightening weapon.
With a design service history spanning nearly 70 years, the MG-42 is the second-longest serving machine gun in the world; only the Browning M2 .50 caliber heavy machine gun has been around longer. The MG-42 lowered production costs and changed the nature of machine gun use within the infantry squad in a revolutionary way.
Copyright 2011 by David Tong and/or chuckhawks.com. All rights reserved.