Post by .x.x.x. on Jun 24, 2006 9:15:32 GMT 1
Maschinengewehr 42 / MG42
The Maschinengewehr 42, or MG42 was a machine gun that was developed for and entered service with Germany in 1942, during World War II. The 7.92 mm rifle caliber weapon was developed from, and was intended to supplant the MG34 machine gun, though both would continue to be used and manufactured until the end of that war.
With possibly the highest rate of fire of any single-barreled light machine gun, resulting in a distinct muzzle report, and a proven record of reliability, durability, simplicity, and ease of operator use, the MG42 eventually gathered a reputation as being one of the best infantry machine guns ever made. More modern designs (such as the M60 or FN MAG) are often compared to the MG42, which is given as probably the best example of a general-purpose machine gun; and this gun is listed alongside other World War II vintage machine guns such as the Browning M1919 '.30 cal' and Bren Gun, and a few selected others. The MG42's lineage continued past Nazi Germany's defeat, forming the basis for the nearly identical MG1, and subsequently improved into the still very similar MG2, which was in turn followed by the MG3. It also spawned the MG42/59; it and the MG3 were in service with many armies during the Cold War and continue to be so into the 21st century
History of MG42
Development of the MG42 was by Metall und Lackierwarenfabrik Johannes Grossfuss AG and resulted from further attempts at improving on the MG34, particularly making them easier to mass-manufacture. The internals were still a short recoil system like the MG34, but the bolt locking system was a design originally patented by Edward Stecke of Poland.
A limited run of about 1,500 of its immediate predecessor the MG34/41 had been completed in 1941 and tested in combat trials. It was officially accepted, and the main manufacturing of the production design began in 1942; contracts going to Grossfuss, Mauser-Werke, Gustloff-Werke, and others. Production during the war amounted to over 400,000 (17,915 units in 1942, 116,725 in 1943, 211,806 in 1944, and 61,877 in 1945). It could be produced in roughly half the number of man-hours of the MG34, using less metal in the process.
One of the weapon's most noted features was its comparatively high rate of fire of about 1,200 rounds per minute, with some versions up to 1,800 rounds per minute; much faster than the British Vickers machine gun at 600 round/min. At such a high rate the human ear cannot easily discern the sound of individual bullets being fired, and in use the gun makes a sound described as like "ripping cloth" and giving rise to the nickname Hitler's Buzzsaw, or, more coarsely, Hitler's zipper. The gun was sometimes called Spandau by Allied troops from manufacturers plates noting the suburb of Berlin where some were produced.
So distinct and terrifying was the weapon, that the United States Army created training films to aid its soldiers in dealing with the psychological trauma of facing the weapon in battle. The high rate of fire had resulted from experiments with preceding weapons that concluded that since a soldier only has a short window of time to shoot at an enemy, it was imperative to fire the highest number of bullets possible to increase the likelihood of a hit. (This principle was also behind the Vickers GO aircraft gun.)
In the late 1930s, the MG34 had proved satisfactory. However, it did have its drawbacks, such as sensitivity to dust and comparatively expensive production. One attempt at improvement was the MG34S, an incremental improvement on the basic 34 design. A much bigger improvement would come from a design firm, Metall-und-Lackierwarenfabrik Johannes Grossfuss AG, experts in pressed and punched steel parts. Their efforts resulted in a dramatic reduction in complexity — it took 75 man-hours to complete the new gun as opposed to 150 man-hours for the MG34, and cost 250 RM as opposed to 327 RM.
The resulting MG39 (redesignated MG42 when adopted in 1942) remained largely similar to the earlier MG34, a deliberate decision made in order to maintain familiarity. The only major change from the gunner's perspective was dropping the drum-feed options, leaving it with a loose belt of ammunition only, and to further increase the rate of fire. Although made of "cheap" parts, the prototypes also proved to be considerably more rugged and resistant to jamming than the somewhat "temperamental" MG34.
The MG42 weighed 11.6 kg in the "light" role with the bipod, lighter than the MG34 and easily portable. The bipod, the same one used on the MG34, could be mounted to the front or the center of the gun depending on where it was being used. For sustained fire use, it was matched to the newly-developed Lafette 42 tripod, which weighed 20.5 kg on its own. The barrel was lighter than the MG34's and heated more quickly, but could be replaced in seconds by an experienced gunner.
The operating crew of an MG42 consisted of three men. The gunner, the ammunition loader (also barrel carrier), and the spotter. The gunner of the weapon was preferably a junior non-commissioned officer. It was possible for operating crews to lay down a non-stop barrage of fire, ceasing only when the barrel had to be replaced. This allowed the three man crew of an MG42 to tie up significantly larger numbers of enemy troops. Both the Americans and the British trained their troops to take cover from the fire of an MG42, and assault the position during the small window of barrel replacement. It should be noted that the high rate of fire of the MG42 sometimes proved a liability — mainly in that, while the weapon could be used to devastating effect, it could quickly exhaust its ammunition supply. For this reason, it was not uncommon for all soldiers operating near an MG42 to carry ammunition on their person, thus providing the MG42 a backup source of ammunition when its main supply was exhausted.
Operation
The MG42 is roller-locked and recoil-operated with gas assist. The roller-locked bolt assembly consists of a bolt head, two rollers, a striker sleeve, bolt body, and a large return spring, which is responsible for pushing the bolt assembly into battery (the locked position) and returning it there when it is unlocked and pushed backwards by the recoil of firing or by the charging handle. As the striker sleeve is movable back and forth within the bolt assembly, the return spring is also responsible for pushing the striker sleeve forward during locking (described below). The bolt assembly locks with the barrel's breech (the end the cartridge is loaded into) via a prong type barrel extension behind the breech. As it is recoil-operated and fired from an open bolt, the weapon must be manually charged with the side-mounted charging handle.
The roller-locked recoil operation functions as follows: two cylindrical rollers, positioned in tracks on the bolt head, are pushed outwards into matching tracks in the barrel extension by the striker sleeve and lock the bolt in place against the breech. Upon firing, rearward force from the recoil of the cartridge ignition pushes the striker assembly back and allows the rollers to move inwards, back to their previous position, unlocking the bolt head and allowing the bolt assembly to recoil, extract the spent cartridge, and strip a fresh cartridge from the belt. The return spring then pushes the bolt assembly forwards again and the sequence repeats as long as the trigger is depressed. The MG42 is capable of fully-automatic fire only. Single shots are exceptionally difficult, even for experienced operators, due to the weapon's rate of fire. The weapon features a recoil booster at the muzzle to increase rearwards force due to recoil, therefore improving functional reliability and rate of fire.
The MG42, as do the majority of machine guns, fires from an open bolt, meaning the bolt (not the firing pin) is held in a rearward position when the trigger is not depressed. Depressing the trigger releases the bolt assembly, of which the firing pin is a component.
The shoulder stock (or butt) is designed to permit gripping with the left hand to hold it secure against the shoulder. Considerable recoil otherwise causes the stock to creep from its intended position. If the weapon is not properly "seated" on the bipod, a prone gunner may be pushed back along the ground from the high recoil of this weapon
Variants and developments
In 1944, the acute material shortages of the Third Reich led to a newer version, the MG45 (or MG42V), which used steel of lesser quality, reduced weight to only 9 kg, and yet further increased the maximum rate of fire. First tests were undertaken in June 1944, but development dragged on and eventually only ten were ever built. The MG42V had some influence in the post-war development of roller-delayed blowback system, as employed in Heckler & Koch modern small arms.
The American military tried to copy the MG 42 during the war, the new version being adapted for the 30-06 cartridge. However, a design flaw in the prototype and the realization that the cartridge might be too strong for the gun to handle resulted in the discarding of the project. However, its belt-feeding mechanism was adopted for the design of the M60.
The MG42, with small modifications, resulted in the MG42/59 and Rheinmetall MG3, which is the primary general-purpose machine gun of the modern German army (Bundeswehr). A number of other armies around the world have adopted versions of the original, especially the MG3, and it remains in widespread service today. The U.S. Army's M60 uses a modified belt-feed mechanism from the MG42 (developed from the 34). The T161 beat the FG42 derived T52 during tests in the 1950s to become the M60. The T161 used a different gas system and was easier to make than the T52, but they both used a similar belt-feed and basic configuration.
* Rate of fire: variable, from 1,100 round/min to 1,600 round/min or more depending on installed bolt weight (different weight bolt components introduced to regulate rate of fire, lighter assemblies providing faster rates of fire). Throat erosion and component wear also introduced significant variation. Up to 1,800 round/min on the MG45 or without "recoil booster" (Rückstossverstärker)
* Changes parts: barrel in 3 to 7 seconds, barrel and lock in 25 to 30 seconds.
The MG42 was adopted by a number of armed organizations after the war, and was copied or license-built as well. Yugoslavia license-built the MG42 as the M53, retaining the 7.92 x 57 mm caliber.
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