Target Sports

MODERN MILITARY MASTERPIECES: ASSAULT RIFLE DESIGNS

Created on 14th May 2009

LAURIE HOLLAND begins a new series on the world's most important cartridges, this month looking at German rifle designs

OVER THE next eight issues I'll look at some of the world's most important cartridges - ‘assault rifle designs'. This will include the German 7.92X33mm, Soviet 7.62X39mm, British 7mm, US 7.62X51mm, Swiss 7.5X55mm, US 5.56X45mm, Soviet 5.45X39mm and US 6.8X43mm. Why are they significant? They represent vast amounts of national effort and treasure spent in their development and manufacture, and like it or not, four are now ubiquitous. These rifles can be seen in every corner of the planet carried by government soldiers, police officers, UN peacekeepers, and by ‘irregulars'.

There are odd men out: the British designs, Swiss 7.5 and American 6.8 - the first for the reason that none were adopted. The Swiss cartridge dates from the early years of the last century, but I've included it as the design was unique in successfully making the transition from bolt-action to selective-fire rifle. Finally, the 6.8mm Remington SPC is only issued to American special forces.

Intermediate

After 1918, the Germans studied the bitter lessons of defeat and decided the next war would reward whoever maximised firepower and mobility, the latter requiring lighter weapons. Infantry tactics and equipment were influenced by the success of Stosstruppen (assault troops) used in the last year of WW1, comprising small breakthrough units of highly trained men armed with the lightest weapons then available - short rifles, early submachine-guns, grenades, sharpened entrenching spades - who hit Allied positions fast and hard, causing chaos and breaks in the line.

Moreover, studies had shown that rifle fire was ineffective above 300m, suggesting most of the weight and ballistic potential of the 7.92X57mm cartridge was wasted (although still required by machine-guns). As Germany rearmed, some factions pressed for the development of automatic rifles firing an ‘intermediate' cartridge that filled the size and power gap between the 9mm submachine-gun and 7.92 Mauser rifle cartridges. Although this development was resisted by senior officers, DWM, Geco and RWS undertook work on such designs, mostly 7mm calibre, during the 1930s. However, the assault rifle as we know it was really set in train in 1938 with an armaments department contract to Polte of Magdeburg to develop a mid-range cartridge. While earlier work had involved fresh designs, Polte retained as many features of the 7.92mm rifle cartridge as possible to simplify production, creating a severely truncated version employing a lightweight bullet, the design finalised over 1940-41.

MKb42, MP43, StG44

The army's smallarms research and development office placed a contract with Haenel in Suhl to come up with a suitable rifle - this company's chief designer being Hugo Schmeisser who had great experience in the field. Prototype 7.92X33mm Maschinen-Karabiner (automatic-carbines) appeared during 1941, and rapidly progressed so troop trials rifles proved largely satisfactory in action on the Eastern Front late the following year. The design now designated the MKb42 was adopted in mid-1943 as the MP43 (MP: Machinen-Pistole or submachine-gun) with some user-requested refinements, and the cartridge put into production as the PP43m.E.

(Pistolen-Patrone 1943 mit Eisenkern, or pistol cartridge of 1943 with iron core bullet). The reason for the designation changes was that Adolf Hitler had explicitly forbidden the development of new rifles. As the military situation moved in the Russians' favour during 1943, the heavily outnumbered Germans desperately needed more firepower - a situation that worsened monthly as the brutal war in the East ground down their forces. The MP43 was an ideal response with its increased rate of fire over the Kar98k bolt-action rifle, but Adolf Hitler's hostility to rifle developments was a major obstacle. However, when the army eventually dared provide a demonstration, a delighted Fuhrer gave it his approval, also producing the ‘assault rifle' moniker, the rifle re-titled SturmGewehr 44.

The StG44 was a gas-operated selective-fire (semi or fully-automatic operation according to the position of a selector lever) short rifle (16.5" barrel) that operated from a closed bolt. In appearance, think AK47 with a large ‘banana' magazine, but uglier, cruder and heavier too despite large-scale use of pressed sheet-steel components.

Kurz

This cartridge frequently has the suffix Kurz (short) attached, as in 7.9mm, 7.92 or 8mm Kurz. No doubt soldiers and supply officers used these unofficial names to differentiate it from standard 7.92X57mm Mauser rifle and machine-gun cartridges. The case is short, measuring just a mere 1.3" or 33mm, the complete cartridge 1.88". The case used the older Mauser case-head and extractor groove, with the lower body diameter dimensions unchanged, simplifying tooling and allowing use of standard stripper clips, which slotted onto the StG44's 30-round magazine top to fill it. The 7.92X57's case-neck diameter remained, but it was shortened to suit a shorter bullet. Another feature is severe body taper, deemed necessary with steel cases that can cause extraction problems. Nominal bullet weight was 125gn, around 23gn of extruded powder producing 2,247fps MV. The pointed boat-tailed bullet retained its big brother's 0.323" diameter simplifying manufacture, but was shortened to an inch, seated deeply with its base at the bottom of the case-shoulder. Steel was primarily used throughout its service life, a swaged mild steel core surrounded by a lead sheath, then a steel outer jacket plated with gilding metal alloy. The effective range was officially 800m to keep the Führer on-side, but tests suggested half that as being practical.

Milestone

Around 425,000 rifles were produced, but most never saw action as ammunition supply lagged behind. With the majority appearing in the last nine months of the war, they had no effect on its outcome. Those that were issued went to elite units, often Waffen SS, and deployment was overwhelmingly in the East, although some found themselves facing the Americans and British in the last six months of war.

The development of the rifle and cartridge is therefore a milestone, the first true assault rifle using an ‘intermediate' power cartridge. Let's look at some issues. The standard WW2 ration of 70 7.92 Mauser rifle cartridges totalled over 4lb, while the same weight of 7.92X33mm examples saw the soldier given 115. Sierra's Infinity recoil calculator says the heavy-ball 7.92 Mauser number produced 17.1ft/lb recoil energy when fired in the Kar98k bolt-action rifle, reduced to 4ft/lb by the short cartridge in the StG44, the reason for its controllability in full-auto fire. Reduced recoil impulse also allows designers to employ simpler, lighter mechanisms and parts made from stampings to reduce materials and skilled labour input.

Postwar, the Allies' ordnance staffs were aware of this system from captured examples and documents. Of the four key NATO founders, Britain, Belgium, Canada and the USA, the first three were deeply impressed by the SturmGewehr - the last, not at all. This divergence of views later led to a falling-out within NATO and major ramifications for the organisation's weapons design and procurement, as will be seen in future issues. However, there was no doubt at all about the significance of the 7.92 Kurz and StG44 in Moscow, as we'll see next month when I cover the Soviet 7.62X39mm cartridge.