Fallschirmjagergewehr 42 (FG 42)

Image credit:  Senich, Peter, The German Assault Rifle 1939-1945, Paladin Press, Boulder, Colorado: 1987  Page 240

SPECIFICATIONS Type:  Selective Fire Paratroop Rifle System of Operation:  Gas, Turning Bolt Caliber:  7.9x57mm Mauser Capacity:  20 round box magazine Sights front: Blade, drift adjustable for windage  Sights, rear:  Elevation adjustable diopter Length: 37" Weight (unloaded): 9.93 lbs Barrel: 19.75"

German paratroop units were, unlike their allied counterparts, were not part of the army (Wehrmacht).  Rather, they were a specific province of the German air force, the Luftwaffe.  These elite Luftwaffe formations were originally provided with the same K98k bolt action carbine, MG34/MG42 machineguns, and MP38/MP40 submachineguns as regular infantry formations.  Early combat experiences in World War Two indicated that these weapons were not well suited to the needs and exigencies of airborne assaults.  Consequently, the Reichluftsfahrtministerium (RLM), or Reich Air Ministry specified a requirement for a long-range, selective fire rifle that would act as a general purpose shoulder arm, replacing the bolt action rifle, submachinegun and light machinegun.  It was hoped that the single arm would simplify logistics while augmenting the individual paratrooper's firepower.

Use of the standard service 7.9x57mm ammunition was mandatory, and design efforts went forward with the intent of producing a specialized weapon that would offer the capabilities of a light machinegun in a package no larger than an ordinary bolt action rifle.  Since the Heereswaffenamt, the Wehrmacht's Weapons Office was the key player in German small arms development, the Luftwaffe initially sought to foment the development program with the Wehrmacht's assistance.  The Wehrmacht, however, thought the project to be specious at best and declined to participate.  As a result, the RLM took the project, lock, stock and barrel, directly to German weapons manufacturers.  The RLM solicited Gustloff, Mauser, Grossfuss, Haenel, Rheinmetall-Borsig, and Krieghoff to participate in the FG42 development project.  Of these firms, only Krieghoff and Rheinmetall-Borsig actually submitted prototype weapons based on the Luftwaffe's requirements.
 

The two prototypes were tested by the Luftwaffe Weapons Development Branch (GL/C-E6) at Tarnewitz through the middle of 1942, and the Rheinmetall gun was selected for procurement as the

Rheinmetall FG42 Prototype Image credit:  Senich, Peter, The German Assault Rifle 1939-1945, Paladin Press, Boulder, Colorado: 1987  Page 240

FG42.  The Rheinmetall design was the work of Louis Stange, the chief of small arms design for the Sommerda works in Thuringia.  Despite this official selection, the FG42 design was never "set in stone."  The Luftwaffe's requirements were in a continual state of flux, and there were a constant series of remedial changes to the original design.  Indeed, if only the known design changes were taken into account, the number of FG42 variants would be far greater than three, the number usually quoted.  Interestingly, the Luftwaffe never used any nomenclature to distinguish between the versions.

The FG42 is a magazine fed, gas operated, turning bolt design that traces its lineage back to the Lewis light machinegun of World War One, and its descendants to the U.S. M60 general purpose machinegun.  When the gun was fired, expanding high pressure gasses forced the bullet down the barrel.  As the bullet passed the gas port, located approximately one third the barrel's distance from the chamber, some of the high pressure gas was vented into a cylinder beneath the barrel.  This gas forced a long gas piston rapidly to the rear.  As the piston moved to the rear, its vertical lug engaged a spiral cam slot on the bolt.  As the lug moves rearward against the cam slot, the bolt is first rotated, bringing the locking lugs out of their recesses, and the forced to the rear.  As the bolt moves to the rear, the fired case is extracted and ejected.  The rearward motion of the bolt and piston is arrested by the action of the recoil spring and buffer on the piston.  At this point the recoil spring forces the bolt/piston group forward again.  As the bolt moves foreward, a fresh cartridge is stripped from the magazine by the bolt into the chamber, and the bolt is then rotated into the locked position.

The FG42's sear mechanism is interesting as it was designed to fire from a closed bolt for semiautomatic fire and an open bolt for fully automatic fire, so as to permit accurate single shots, yet permit the best possible cooling when operating in fully automatic mode.  The combination of an in-line stock configuration and side mounted magazine placed both the center of gravity and the center of the butt almost directly in line with the center of the bore, providing a surprising degree of control over a conventional automatic rifle firing a full power service cartridge.    As a result, the FG42 was an automatic rifle with the characteristics of a lightweight machine gun with provision for special attachments.

PHYSICAL CHARACTERISTICS - Early FG42

• The butt was made of heavy gauge sheet metal stampings that were ribbed for added strength.
• The receiver was a machined alloy forging with an integral magazine housing on the left side and an ejection port on the right.
• Because of the position of the magazine housing, the bolt/piston mechanism was able to extend into the butt, thereby reducing the gun's length without having the magazine housing interfere with the location of the pistol grip.
• The pistol grip assembly was an entirely discrete unit that contained the trigger mechanism, the selector, safety, and the firing-system components.  It was made from sheet metal stampings.  Grasping grooves were pressed into the grip during the stamping process.
• Both the butt and the pistol grip assembly were formed as two halves that were then welded together.
• The handguard was made of wood with openings in the upper surface that permitted air to flow over the barrel, aiding in cooling.  The handguard also had a form of palm stop to ensure that the rifleman's hand would not come into contact with the rapidly cycling operating handle during firing.
• A folding bipod made of stamped steel was hinged to the barrel collar directly forward of the handguard.  When folded, the legs formed an additional grasping surface as well as a scabbard for the rifle's self-contained cruciform spike bayonet.
• The barrel was threaded to the receiver and secured by a lateral pin.  It was fitted with a combination flash hider and muzzle brake, and had a threaded muzzle which served as a mount point for a grenade launcher.
• Feed mechanism was a 20 round horizontal box magazine.  10 round versions were also manufactured.

Production Version of Rheinmetall FG42 Image credit:  Senich, Peter, The German Assault Rifle 1939-1945, Paladin Press, Boulder, Colorado: 1987  Page 248

The prototypes manufactured by Rheinmetall were manufactured largely of chrome steel.  While an excellent material for gun manufacture, chrome steel was a strategic alloy in short supply.  When the Luftwaffe was permitted to build 3,000 FG42 trials rifles, the material specification was amended to permit manufacture

Krieghoff took advantage of the production halt to register a major objection to the amount of forging, machining, and close tolerance work necessary to produce the Rheinmetall design.  Given the exigencies of wartime production needs, the objection met with significant agreement in German ordnance circles.  In addition to the production difficulties, field reports indicated that the FG42's light weight worked against it in the long range, full automatic fire support role.  There were also allegations that the gun was simply too fragile for the rigors of sustained combat.  Krieghoff was rewarded with a contract to redesign the FG42 so as to simplify production  and remedy the basic flaws affecting performance and durability.

The Krieghoff modifications were extensive, affecting almost every aspect of the FG42.  Among the most notable changes were:

• The front sight bracket and the bayonet mount were changed.
• The bipod was strengthened, the locking detents made more positive, and moved forward towards the muzzle.
• The stock was now made of laminated wood
• Spring loaded dust covers were fitted to the magazine housing.
• The angle of the grip was changed, and the entire handgrip assembly redesigned to be readily detached.
• The safety lever was moved to the rear of the selector.
• The handguard configuration was changed.
• A spent brass deflector was added
• An adjustable gas regulator was added

While the design of the FG42 didn't lend itself to simple mass production techniques, the Krieghoff gun was a dramatic improvement in production engineering.  While the original Rheinmetall design's receiver was a complex forging that called for extensive machining, the new Krieghoff receiver

Krieghoff FG42 Image credit:  Senich, Peter, The German Assault Rifle 1939-1945, Paladin Press, Boulder, Colorado: 1987  Page 256

In effect, these modifications were tacit admissions that the combination of a short barrel, light weight, and a full power cartridge made for a rifle that was very difficult to control.  Consequently, further modifications almost always included an increase in system weight.  Indeed, the last model FG42 was to be more than two pounds heavier than the first Krieghoff model.  Despite this, the rifle suffered from controllability problems up to the end of production.  Despite advances in firearms technology and production techniques for fifty years after the FG42's entry into service, the dilemma of controllable, lightweight fully automatic rifle firing a full power service cartridge was never solved.  The last generation of full power battle rifles - the FAL, the M14, and the G3 - all suffered from poor controllability in the fully automatic mode.

Given the FG42's inability to supplant the light machinegun, and the comparable performance of the 7.9x33mm Sturmgewehr series of firearms, the Wehrmacht adamantly championed the universal acceptance of the 7.9x33mm weapons and the termination of  FG42 production and development.  Despite this, the Luftwaffe never officially adopted the short cartridge.

Both the Wehrmacht and the Luftwaffe continued to study and evaluate the FG42 during the length of the its service life.  Wehrmacht tests in early 1944 indicated that the FG42 was incapable of replacing the light machinegun.  Additionally, the Heereswaffenamt indicated that the FG42 offered no performance advantage over the MP43 out to 400 meters.  As a result, the Wehrmacht demanded that the short cartridge assault rifle series be given preference.  As the war progressed, the German armed forced stood more and more on a defensive posture. More and more frequently the Fallschirmjager units served as regular infantry, thus obviating the need for a special airborne assault rifle.  Despite all this, and for some reason known only to the inscrutable logic of German wartime procurement, the Luftwaffe was given permission to mass produce the FG42 in late 1944.  Krieghoff built approximately 5,000 FG42's before wartime exigencies brought production to a halt in early 1945.

FG42's produced by Krieghoff bear the "fzs" maker code.  While this was originally the code for the Heinrich Krieghoff Waffenfabrik, Suhl, later evidence suggests that the FG42 was actually developed and produced at what the German ordnance establishment referred to as Plant No. 10 - Luttich.  Prior to the war Plant No. 10 had been known as the Luttich Plant and was part of the holdings of the Krieghoff organization, which had purchased the Liege, Belgium facility in the late 1930's from the Anciens Etablissements Pieper (makers of the Bayard M1908 pistol) as a means of expanding production capacity.  FG42's were also produced by the L.O. Dietrich firm of Altenburg (production code gcy), with replacement parts being made by I.C. Wagner of Mulhausen (production code gal).  All told, approximately 7,000 FG42's were made, breaking down to 2,000 early and 5,000 late models.  Most FG42's saw use on the western front during the war.
 

Early fzs Receiver Image credit:  Senich, Peter, The German Assault Rifle 1939-1945, Paladin Press, Boulder, Colorado: 1987  Page 243

Late fzs Receiver Image credit:  Senich, Peter, The German Assault Rifle 1939-1945, Paladin Press, Boulder, Colorado: 1987  Page 265

gcy Receiver Image credit:  Senich, Peter, The German Assault Rifle 1939-1945, Paladin Press, Boulder, Colorado: 1987  Page 278

The FG42, despite being produced in limited numbers, was one of the most influential firearms of the Second World War.  The US Army manifested a great deal of interest in the FG42.  A post war design project initiated by the US Army Ordnance Corps married the belt feed system of the MG42 with the FG42's operating mechanism.  The project was refined for a number of years, and resulted in a direct descendant of the FG42 - one of the most prolific automatic weapons to be adopted by a major power - the US M60 General Purpose Machine Gun.

7.92mm Light Automatic Machine Gun T44 - Design Basis for the M60 GPMG Image credit:  Senich, Peter, The German Assault Rifle 1939-1945, Paladin Press, Boulder, Colorado: 1987  Page 280

 

BIBLIOGRAPHY

Senich, Peter R., The German Assault Rifle 1935-1945, (Paladin Press, Boulder, Colorado: 1987)
 

The German Assault Rifle is available from IDSA Books.  Click on the image to order:

 
 

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