Friday 28 October 2011

MP38, MP40



MP-40 submachine gun, with shoulder stock opened.


Caliber: 9x19mm Luger/Para
Weight: 4,7 kg loaded, 4,03 kg empty
Length (stock closed/open): 630/833 mm
Barrel length: mm
Rate of fire: 500 rounds per minute
Magazine capacity: 32 rounds
Effective range: ca. 100 meters


The M.P. 38 submachine gun started its life under requirements from German Heereswaffenamt (HWA, Army Weapons Office), which saw the need for a compact submachine gun, suitable for use by armored vehicles crews and paratroopers. German arms-making company Erfurter Maschinenfabrik Gmbh,better known under its trade name Erma, began the development of a new weapon under HWA specifications. It must be noted that a new submachine gun was not built from the scratch; instead, it was just an evolution of a rarely known prototype weapon, provisionally known as Erma MP-36. MP-36 was a compact version of the better known Erma EMP submachine gun, but fitted with now-familiar underfolding metallic shoulder stock and bottom-feed magazine, which was slightly canted forward to accommodate EMP magazines. MP-36 was a selective-fired weapon, and in fact the improved MP-38 was a simplified version of its little known predecessor, adapted for different magazine. Therefore, it took only few months before the new weapon was ready for official adoption and mass production. Manufacture of a new submachine gun,designated as MP-38, commenced in summer of 1938, at Erma, and later on also at C.G. Haenel.
The gun was manufactured for just 2 years, when it was replaced in production by externally similar, but less expensive MP-40, which used more stamped parts instead of machined parts, found in MP-38. There also were minor variations in design of MP-38, such as shape of cocking handle etc. MP-40 was also produced in a number of variations, which differed in shape of certain parts; also, toward the end of the war, several production shortcuts were introduced to save the costs of manufacturing. probably the most interesting variation of the MP-40 were the MP-40-II and MP-40-II. These guns featured dual magazine housings which hold two magazines in a laterally sliding bracket. This increase the total ammunition capacity "in the gun" to 64 rounds, in a desperate attempt to catch up with 71-round magazine capacity of Soviet PPSh-41. The later variant, MP-40-II, was made in limited numbers, but turned out to be a failure - sliding dual-magazine housing was a constant source of jams and failures, and was very sensitive to dirt and fouling.
Nevertheless, MP-38 and especially MP-40 submachine guns were of good design,and set the pattern for so called "second generation" of submachine guns ("first generation" being represented by the wood-stocked and carefully machined MP-18, MP-28 and the like). The second generation weapons usually were of compact design, and made using mostly steel stampings and pressings, or castings.
It also must be noted that many MP-40 that survived the WW2, continued to serveup until late 1970s or early 1980s, in few European armies such as Austrian or Norwegian.
Both MP-38 and MP-40 submachine guns are blowback operated weapons that fired from open bolt. Both weapons were full-automatic only, but relatively slow rate of fire permitted for single shots with short trigger pulls. The proprietary bolt system with telescoped return spring guide served as a pneumatic recoil buffer,helping to decrease rate of fire to a very manageable level. The bolt handle was permanently attached to the bolt on early MP-38's; on late production MP-38's and MP-40's bolt handle was made as a separate part and also served as a safety- pushing the head of bolt handle inward locked the bolt either in cocked or forward position. Lack of such feature on early MP-38's resulted in field expedients such as leather harnesses with small loop, used to hold the bolt in forward position. One unusual feature on most MP-38 and MP-40 submachine guns was an aluminum or plastic rail under the barrel, which served as a barrel support /protector when firing over the board of armored personnel carrier. The short handguard was made from plastic and was located between magazine housing and pistol grip; barrel lacked any heat insulation, which often caused burns for supporting hand. Folding shoulder stock resulted for compact weapon when folded,but it was insufficiently durable for combat use and hand-to-hand combat.Single-feed, double-row box magazine was another weak point of the design; it was hard to load without additional help, and often caused jams.

Maschinengewehr 34 (MG34)

MG-34 as a light machine gun, with 50 rounds belt drum-like box.


Caliber: 7.92x57mm Mauser (also known as 7.9mm Mauser or 8mm Mauser)
Weigth: 10.5 kg on bipod, empty
Length: 1219 mm
Length of barrel: 627 mm
Feeding: belt, 50 or 250 rounds; double drum magazines, 75 rounds.
Rate of fire: 900 rounds/min
Muzzle velocity: 755 m/s (may vary depending on type of ammunition used)
Maschinengewehr-34 (Machine gun, model of 1934), or MG-34, is known as a main infantry support weapon of the Wehrmacht (Hitlers' German Army) through first half of the World War 2, and main vehicle (tank) machine gun of the same during the whole war. MG-34 also is nototious for being the first ever true Universal machine gun, that could be used as a light machine gun from bipod, as a sustained fire, medium machine gun on tripod, as a tank or AA gun.
MG-34 was designed in the early 1930s by the team lead by Louis Stange at Rheinmetall, leading German arms manufacturer at that time. Final design, adopted for service in 1934, incorporated numerous features from experimental prototypes built by Rheinmetall, Mauser-werke, and others. As was requested by German army, it was a truly universal machine gun, capable of different roles. It was put into production circa 1935, and remained an official MG of the Wehrmacht until 1942, when it was oficially replaced my more reliable and cheap MG-42. But, despite this, MG-34 continued to serve untill the end of WW2, mostly as a tank gun, because it was better suited for this role than the MG-42.
MG-34 is a recoil-operated, selective fire weapon. It uses short recoiling barrel with muzzle recoil booster which also serves as a flash hider. Barrel locking is achieved by the rotating bolt head, with interrupted threads locking lugs, that lock into the barrel extension. Bolt head has a set of rollers, located just behind the lugs. These rollers are used to rotate bolt heads to lock and unlock, when riding inside the curved grooves, cut on the inner walls of the receiver. Rollers also act as a bolt accelerator, when bolt unlocks, due to inter operation with the barrel extension. Tubular receiver is linked to the tubular barrel sleeve by the swinging stud, set at the right side of the receiver, so receiver can be turned up and to the right relatively tho the barrel sleeve, thus exposing the barrel rear end. When receiver is opened, barrel can be simply withdrawn from its sleeve to the back, but when barrel is hot, this requires some sort of the heat protection, so MG-34 operator had to use asbestos glove which was a standard acessory to the gun. MG-34 usually was issued with belt feed, which was operated by the stud on the top of the bolt body. Belt feed could be easily set up to take the belt from the left or from the right side of the gun. With special replacement feed cover, a double-drum, saddle-type 75 rounds magazines can be used. MG-34 was a selective fire weapon, with mode of fire being controlled by dual trigger. A pull on the upper part of the trigger produced single shots, while a pull on the lower part produced full auto bursts.
Being an universal MG, MG-34 could be used in different configurations. As a light MG, it was used from light, folding bipods, which could be set up either under the muzzle or under the guns' center of gravity, allowing for better stability or better field of fire, respectively. In this mode MG-34 was usually fed from 50-rounds truncated-cone belt boxes, made of tin. Belt boxes were cillped to the receiver and allowed the gun to be carried loaded withouth dangers of belt being jammed.
In sustained fire role, MG-34 was mounted on the special tripod of very complicated and expensive design, called Lafette-34. This tripod allowed for direct or indirect fire missions, and was equipped with recoil dampers, special fire control unit and an optical scope mount. With the use of the special adapter, this tripod also can be used for antiaircraft role. For dedicated air-defence missions a special, lightweight AA tripod was also available.


MG 42 machine gun in LMG role, left sideview, with bipod extended.


With adoption of the MG 34 machine gun the Wehrmacht had the weapon that was envisaged some 20 years before, and the MG 34 bears the distinction of being the first practical universal (or general purpose) machine gun. While the MG 34 was good and practical, it was certainly not ideal. German experts wanted their machine guns to fire faster, while being simpler and less costly. A high rate of fire was desirable both for AA applications and for surprise flanking fire against targets moving through the battlefield. As early as 1937 HWaA issued a request for the next new universal machine gun,and three companies received development contracts – Johannes Grossfuss AG, Stubgen AG and Rheinmetall-Borsig AG. In 1939 a commission selected the Grossfuss-made MG 39 prototype for further development. Designed by engineer Gruner (often wrongfully referred to as Grunow) and small arms designer Horn, new weapon, in accordance with HWaA request, had a stamped steel construction, combined with locked breech, short recoil action. Initial trials suggested that the Grossfuss MG needed further development, and in late 1941 a small batch(about 1500 pieces) of improved guns was manufactured for troop trials as the MG 39/41.
The new machine gun, while being made tolower standards of fit and finish, proved to be quite functional and reliable (a feature that the much more “refined” MG 34 lacked, especially in the mud and snow of the Russian front). Subsequently, it was officially adopted as the MG 42, and production commenced later the same year.
In general terms, the MG 42 was a great success. It fulfilled the roles of a light machine gun on a bipod, a medium machine gun (on a newly developed Lafette 42 tripod), and an anti-aircraft machine gun, mounted in single and twin installations, ground and vehicle-mounted.

MG 42 machine gun in MMG role, on infantrytripod mount Lafette 42.
It was relatively inexpensive to make and required less raw materials than the MG 34, and it was simple to maintain and use. On the minus side, it had a somewhat excessive rate of fire, usually quoted as 1200 rounds per minute, although German WW2 era manuals listed it as 1500 rounds per minute (25 rounds per second).This rate of fire resulted in excessive consumption of ammunition and rapid overheating. While the extremely rapid barrel change procedure allowed for sustained fire, the resulting accuracy left something to be desired; excessive vibration from recoil, combined with a short sight radius, resulted in degraded long range accuracy compared with earlier MG 34 and,especially, the heavy MG 08 Maxim guns. Nonetheless the MG 42 was an impressive and fearsome weapon, known among Allied soldiers as“Hitler’s saw”, for the sound of the firing which resembled the sound of a giant mechanical saw.
After the WW2 this weapon, unlike other wartime designs, lived on, as in 1958, the FRG (WestGermany) re-instituted its official armed force, known as the Bundeswehr. Since the core of the Bundeswehr was formed of WW2 veterans, it was logical to adopt weapons which were already proven and familiar to the troops; and the MG 42 was one of such weapons. It was,obviously, chambered for a ‘non-NATO’ cartridge, but this was only a minor issue, as the 7.62x51 NATO and 7.92x57 Mauser shared the same cartridge base diameter, and were somewhat similar in ballistics. The real problem, however, was that Germany had lost most manufacturing facilities for the MG 42, so the newly reestablished Rheinmetall concern had to install production facilities from the ground up. The production documentation for original MG 42 machine guns was obtained from Grossfuss company and transferred to Rheinmetall (German government had to pay significant royalties to Johannes Grossfuns for manufacturing rights). Since the preparation for manufacture took sometime, the FRG purchased some ex-Wehrmacht MG 42 weapons from other countries. Those guns were converted to 7.62 NATO by Rheinmetall and officially designated MG 2. The newly produced MG 1 guns went through a number of modifications, which resulted in the definitive MG 3 version,which still is rather close in design to the war-time MG 42, although made to much higher standards of fit and finish. The simplicity, low manufacturing cost and high effectiveness of the MG 3 attracted several other countries, which either bought the guns from Rheinmetall (such as Denmark), or obtained manufacturing licenses and build (or at least have built in the past) the same guns domestically (such as Italy, Iran, Turkey, Pakistan and Yugoslavia). In total, at least twenty armies have used or still are using the MG 3 and its versions.It must be noted that in some countries these guns were used under their "commercial" Rheinmetall designation MG 42/59.
The MG 42is a short-recoil operated, air cooled, belt fed weapon which fires from an open bolt. The barrel is quick-removable, and can be replaced in less than six seconds by a properly trained crew, although an asbestos glove is required to remove the hot barrel.The action of the weapon is operated by the recoil of the locked barrel, assisted by a muzzle booster which uses pressure from the muzzle blast to increase the recoil impulse. Locking is achieved by a pair of rollers, which are forced outwards from the sides of the bolt head to engage cuts in the barrel extension. Locking (outward) movement of the rollers is controlled by the wedge-shaped front part of the bolt body; unlocking(inward) movement of the rollers by the cams made in the receiver. This is a simple and solid system which minimizes the length of parts that are under stress upon discharge, and also minimizes the strain on the receiver. On MG 3 machine guns, two types of bolts are available, with standard weight (about 650 gram) for fast rate of fire and with heavyweight (about 900 gram) for slow rate of fire. It must be noted that those bolts also are used along with different return springs.
The receiver and barrel jacket are made in one unit, and formed from a sheet of rolled steel,cut to shape by pressing and stamping, and then welded and pinned to form a gun housing of generally rectangular cross-section. The front part of the housing serves as a barrel jacket and has a number of oval cooling slots at all sides except the right. The right side of the jacket has one long slot which is used to remove the barrel. The barrel is held in place by a hinged lock, located at the rear of the opening in the right side of the jacket. To remove the barrel, the operator must first lock the bolt in the open position (cock the weapon), and then turn the barrel lock to the right and forward. This will release the barrel and bring its breech area out of the jacket, so it can be grabbed (using the issued asbestos glove or other heat insulation means if the barrel is hot) and pulled back and out of the jacket. The new barrel is then inserted all the way forward and lock then is snapped into place, bringing the barrel into alignment with the action.
Barrel change for MG 42 - barrelis unlatched and its breech part is exposed for removal.
The gun is fed using belts only. Feed direction is from the left to right;the feed is of the one-stage, push-through type. The belt is same as for the MG 34, with steel links with open pockets, assembled into non-disintegrating 50-round lengths. The same MG 34 type “Gurttrommel”50-round drum-type belt containers can be used with the MG 42, and a new type of lightweight plastic 50-round belt container was developed in West Germany by HK and is now issued with MG 3 guns. The belt feed is operated by the reciprocating bolt which has a roller at the top of its body. This roller engages the cam track in the oscillating lever, located in the top-opening feed cover. The lever operates the belt pawls in two steps, on both opening and closing movement of the bolt, resulting in a smooth and positive feed. This two-step belt traction is particularly useful because the high rate of fire results in high-speed belt movement, and this system reduces the strain put on both the feed unit and belt links. Current production MG 3 guns can fire either non-desintegrating or desintegrating belts.
The trigger unit is ofrelatively simple design, and permits for automatic fire only. The manual safety is of the cross-bolt, push button type, located at the top of the pistol grip. The charging handle is located at the right side of the receiver, and is separated from the bolt group (it does not move when gun is fired). Each MG 42 was issued with an integral, adjustable bipod attached near the muzzle; MG 3 guns may have two points for bipod attachment, one near muzzle and another near the center of the gun. In the medium role, the MG 42 was used from the Lafette 42, a complicated foldable tripod with buffered cradle. A wide number of tripods is available for MG 3 guns,as produced in several countries.
The standard sights are open, fully adjustable, and mounted on foldingbases. The universal tripod has provisions for mounting telescopic sights for long range and indirect fire missions.

In parallel with the work carried out in Switzerland (this work resulted in development of the Steyr-Solothurn S2-200, also known as MG 30 in Austrian service or 31M in Hungarian service), during late twenties and early thirties German arms-making concern Rheinmetall continued domestic developments based on WW1-era designs. By the early 1930s Rheinmetall had modified the 1918 pattern “Dreyse” LMG into a magazine fed, light machine gun which was known as Gerat 13 (device 13). Developed in the light of recommendations from German Army experts, this weapon was thoroughly tested and officially adopted by Wehrmacht as MG 13 in 1932. The MG 13 designation was selected as a disguise, in an attempt to represent a newly developed weapon as an older (1913 pattern) model in the eyes of Allied Control Commission which enforced the Versailles treaty. For a short time the MG 13 became the core of German infantry squad. Initially it was issued with a 25-round curved box magazine, but later on a special 75-round twin drum (Doppeltrommel 13) was developed to provide more sustained firepower, especially for AA missions. This double drum was based on, but not interchangeable with, the similar double-drum magazine developed for Luftwaffe’s MG 15 machine gun, which was widely used on German aircraft as an observer’s weapon.

The MG 13 is a short-recoil operated, magazine fed, air-cooled light machine gun. The barrel of the gun can be withdrawn and replaced, but this requires partial disassembly of the gun, as the barrel is withdrawn through the rear of the opened receiver along with its extension and bolt. Locking is achieved by a swinging lever located at the bottom rear part of the barrel extension, just behind the bolt. When in battery, the front arm of the locking lever supports the bolt from behind, locking it in place; unlocking is resisted by a shelf in the receiver, which does not allow the locking lever to swing down. Upon discharge, the barrel, its extension, bolt and locking lever recoil for a short distance. After that short recoil, the front arm of the lever leaves its supporting shelf in the receiver and the rear arm of the lever strikes the cam in the receiver, swinging the front arm down and out of the path of the bolt. A lever-type accelerator is located in the receiver; it acts upon the base of the charging handle to increase the speed of the bolt.
The receiver is relatively short, with top and bottom covers hinged from it. The top cover contains the return spring; opening it automatically disengages the spring from the bolt group. The bottom cover hosts the trigger unit and backplate with an attached shoulder stock.
The MG 13 fires from a closed bolt, using an internal hammer. The trigger is of the rocking type, it allows for single shots and full automatic fire. The selection of the fire mode is made by pressing either the top (single shots) or bottom (automatic) part of the trigger. A manual safety is located at the left side of the receiver, above and behind the pistol grip.
The MG 13 uses only magazine feed. Magazines were inserted from the left side, and the magazine housing has a spring-loaded dust cover. Spent cases are ejected through the opening in the right receiver wall. The original magazines were of the curved box type, holding 25 cartridges in two rows. Box magazines can be refilled using standard 5-round stripper clips. Later on, double drum magazines were developed. These magazines have two drums, with cartridges fed alternatively from each drum. These Double drum (Doppeltrommel in German nomenclature) magazines were different from MG 15 / MG 34 magazines, as the “upper” drum was located asymmetrically relative to “lower” drum, so it would not block the line of sight on MG 13. Double drum magazines were rather expensive and heavy, and notoriously hard to load.
The MG 13 was issued with a detachable bipod of adjustable height. The barrel jacket has two attaching points for a bipod – one near the muzzle and another near the receiver. The shoulder stock is made of steel with leather recoil pads. To save length, the shoulder stock can be folded forward and to the right. The gun can be fired regardless of the position of the stock, as it folds below the ejection port. A carrying handle is provided at the front of the receiver.

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