7.5 cm PaK 40 Antitank Gun.
The first weapon of the German Panzerjäger ( armour hunters or tank hunters) was the humble Panzerbüchse which was in service from 1917 through to 1943. Panzerbüchse literally means “armour rifle” and German anti-tank rifles originated back in 1917 with the Mauser 1918 T-Gewehr, the world’s first anti-tank rifle. It was created as an immediate response to the appearance of British tanks on the Western Front. A single shot manually operated rifle, it enjoyed moderate success, with approximately 15,800 rifles eventually produced. The Panzerbüchse 39 (PzB 39) was the main German anti-tank rifle used in World War II. It was an improvement of the unsuccessful Panzerbüchse 38 (PzB 38) rifle.
German Panzerbüchse development resumed in the late 1930s. In an effort to provide infantry with a man-portable lightweight anti-tank rifle. The task fell to Dipl.-Ing. (certified engineer) B. Brauer at Gustloff Werke in Suhl who designed the Panzerbüchse 38 (PzB 38). It was a manually loaded single-shot weapon with a recoiling barrel. When fired, the barrel recoiled about 9 cm, which opened the breech and ejected the spent cartridge casing. The breech block was then arrested in the rear position, remaining opened for the gunner to manually insert a new cartridge. The gunner then released the cocked breech with a lever at the grip. The breech and barrel would then move forward again and the trigger was cocked in preparation to fire. This rather complicated mechanism was prone to jamming as the system easily fouled in field use.
Although manufactured with pressed steel parts that were spot-welded, because of the complicated vertical breech block mechanism the Panzerbüchse 38 was difficult to manufacture and only a small number of 1,408 PzB 38 rifles were built in 1939 and 1940 at the Gustloff Werke plant; only 62 of these weapons were used by German troops in the invasion of Poland in 1939.
The Panzerbüchse 39 was the next development, and was found to be a major improvement as a result the Panzerbüchse 38 declared obscelescent and production was immediately switched to the Panzerbüchse 39. However it too featured a vertical breech block mechanism and used the same cartridge. It retained the barrel of the PzB 38 and had an only slightly increased overall length of 162.0 centimetres (63.8 in); weight was reduced to 12.6 kilograms (28 lb). Its performance data was basically the same as that of the PzB 38. To increase the practical rate of fire, two cartridge-holding cases containing 10 rounds each could be attached to both sides of the weapon near the breech – these were not magazines feeding the weapon, they simply enabled the loader to extract the cartridges (that he still had to manually insert into the gun) from the conveniently placed magazines. 568 PzB 39 were used by the German army in the invasion of Poland; two years later, at the beginning of the war against Russia, 25,298 PzB 39 were in use by German troops; total production from March 1940 to November 1941, when production ceased, was 39,232 rifles. The PzB 39 remained in use until 1944, by which time it had become hopelessly inadequate against all but the lightest armored vehicles.
OKW recognised the need for a more powerful form of anti-tank weapon and the design of a horse-drawn, 3.7 cm anti-tank gun (designated 3.7 cm Pak L/45) by Rheinmetall commenced in 1924 and the first guns were issued in 1928. However, by the early 1930s, it was apparent that horse-drawn artillery was obsolescent, and the gun was modified for motorized transport by substituting magnesium-alloy wheels with pneumatic tyres for the original spoked wooden wheels. Re-designated the 3.7 cm Pak 35/36, it began to replace the 3.7 Pak L/45 in 1934 and first appeared in combat in 1936 during the Spanish Civil War. It formed the basis for many other nations’ anti-tank guns during the first years of World War II. The KwK 36 L/45 was the same gun but adapted as the main armament on several tanks, most notably the early models of the Panzer III.
The Pak 36, being a small-calibre weapon, was outdated by the May 1940 Western Campaign, and crews found them inadequate against allied tanks like the British Mk.II Matilda, and the French Char B1 and Somua S35. Still, the gun was effective against the most common light tanks, such as the Renault FT-17 and saw wide service during the Battle of France and the T-26 during Operation Barbarossa. The widespread introduction of medium tanks quickly erased the gun’s effectiveness; miserable performance against the T-34 on the Eastern Front led to the Pak 36 being derisively dubbed the “Door Knocker” (Heeresanklopfgerät, literally “army door-knocking device”) for its inability to do anything other than advertise its presence to a T-34 by futilely bouncing rounds off its armor.
Not surprisingly The Pak 36 began to be replaced by the new 5 cm Pak 38 in mid 1940. The addition of tungsten-core shells (Pzgr. 40) added slightly to the armour penetration of the Pak 36. Despite its continued impotence against the T-34, it remained the standard anti-tank weapon for many units until 1942. It was discovered that Pak 36 crews could still achieve kills on T-34s, but this rare feat required tungsten-cored armour piercing ammunition and a direct shot to the rear or side armour from point-blank range.
As the Pak 36 was gradually replaced, many were removed from their carriages and added to SdKfz 251 halftracks to be used as light anti-armour support. The guns were also passed on to the forces of Germany’s allies fighting on the Eastern Front, such as the 3rd and 4th Romanian Army. This proved particularly disastrous during the Soviet encirclement (Operation Uranus) at the Battle of Stalingrad when these Romanian forces were targeted to bear the main Soviet armoured thrust. The Pak 36 also served with the armies of Finland (notably during the defence of Suomussalmi), it was also deployed in Hungary, and Slovakia.
In 1943, the introduction of the Stielgranate 41 shaped charge meant that the Pak 36 could now penetrate any armour, although the low velocity of the projectile limited its range. The Pak 36s, together with the new shaped charges, were issued to Fallschirmjäger units and other light troops. The gun’s light weight meant that it could be easily moved by hand, and this mobility made it ideal for their purpose.
The replacement for the outdated Pak 36 was the 50cm Pak 38. The longer barrel and larger projectile produced the required level of kinetic energy to pierce armour . The PaK 38 was first used by the German forces during the Second World War in April 1941. When the Germans faced Soviet tanks in 1941 during Operation Barbarossa, the PaK 38 was one of the few early guns capable of effectively penetrating the 45 mm (1.8 in) armor of the formidable T-34. Additionally, the gun was also equipped with Panzergranate 40 APCR projectiles which had a hard tungsten core, in an attempt to penetrate the armor of the heavier KV-1 tank. Although it was soon replaced by more powerful weapons, the Pak 38 remained a potent and useful weapon and remained in service with the Wehrmacht until the end of the war.
The 7.5 cm PaK 40 (7.5 cm Panzerabwehrkanone 40) was the next generation of anti-tank gun to see service. This German 7.5 centimetre high velocity anti-tank gun was developed in 1939-1941 by Rheinmetall and used extensively from 1942-1945 during the Second World War. It was the PaK 40 which formed the backbone of German anti-tank guns for the latter part of World War II. Development of the PaK 40 began in 1939 with development contracts being placed with Krupp and Rheinmetall to develop a 7.5 cm anti-tank gun. Priority of the project was initially low, but Operation Barbarossa in 1941 and the sudden appearance of heavily armoured Soviet tanks like the T-34 and KV-1, increased the priority. The first pre-production guns were delivered in November 1941.
In April 1942, Wehrmacht had 44 guns in service. It was remarkably successful weapon and by 1943 the PaK 40 formed the bulk of the German anti-tank artillery.The PaK 40 was the standard German anti-tank gun until the end of the war, and was supplied by Germany to its allies. Some captured guns were used by the Red Army. After the end of the war the PaK 40 remained in service in several European armies, including Albania, Bulgaria, Czechoslovakia, Finland, Norway, Hungary and Romania.
Around 23,500 PaK 40 were produced, and about 6,000 more were used to arm tank destroyers. The unit manufacturing cost amounted to 2200 man-hours at a cost of 12000 RM. A lighter automatic version, the heaviest of the Bordkanone series of heavy calibre aircraft ordnance as the BK 7,5 was used in the Henschel Hs129 aircraft.
The Pak 40 was effective against almost every Allied tank until the end of the war. However, the PaK 40 was much heavier than the 50 cm PaK 38, It was difficult to manhandle into position and its mobility was limited. It was difficult or impossible to move without an artillery tractor on boggy ground.
The PaK 40 debuted in Russia where it was needed to combat the newest Soviet tanks there. It was designed to fire the same low-capacity APCBC, HE and HL projectiles which had been standardized for usage in the long barreled Kampfwagenkanone KwK 40 main battle tank-mounted guns. In addition there was an APCR shot for the PaK 40, a munition which eventually became very scarce.
The main differences amongst the rounds fired by 75 mm German guns were in the length and shape of the cartridge cases for the PaK 40. The 7.5 cm KwK (tank) fixed cartridge case is twice the length of the 7.5 cm KwK 37 (short barrelled 75 mm), and the 7.5 cm PaK 40 cartridge is a third longer than the 7.5 cm KwK 40.
The longer cartridge case allowed a larger charge to be used and a higher velocity for the Armour Piercing Capped Ballistic Cap round to be achieved. The muzzle velocity was about 790 m/s (2,600 ft/s) as opposed to 750 m/s (2,500 ft/s) for the KwK 40 L/43. This velocity was available for about one year after the weapon’s introduction. Around the same time, the Panzer IVs 7.5 cm KwK 40 L/43 gun and the nearly identical Sturmkanone (StuK) 40 L/43 began to be upgraded with barrels that were 48 calibers long, or L/48, which remained the standard for them until the end of the war.
In the field, an alarming number of L/48 cartridge cases carrying the hotter charge failed to be ejected properly from the weapon’s semi-automatic breech, even on the first shot (in vehicles). Rather than re-engineer the case, German Ordnance reduced the charge loading until the problem went away. The new charge brought the muzzle velocity down to 750 m/s, or about 10 m/s higher than the original L/43 version of the weapon. Considering the average variability in large round velocities from a given gun, this is virtually negligible in effect. The first formal documentation of this decision appears on May 15, 1943 (“7.5cm Sturmkanone 40 Beschreibung”) which details a side by side comparison of the L/43 and the L/48 weapons. The synopsis provided indicates very little difference in the guns, meaning the upgrade had little if any benefit.
All further official presentations of the KwK 40 L/48 ( “Oberkommando des Heeres, Durchschlagsleistungen panzerbrechender Waffen”) indicate a muzzle velocity of 750 m/s for the gun. As for the PaK 40, the desire for commonality again appears to have prevailed since the APCBC charge was reduced to 750 m/s, even though case ejection failures apparently were never a problem in the PaK version of the gun.
For reasons which seem to be lost to history, at least some 75 mm APCBC cartridges appear to have received a charge which produced a muzzle velocity of about 770 m/s (2,500 ft/s). The first documented firing by the U.S. of a PaK 40 recorded an average muzzle velocity of 776 m/s for its nine most instrumented firings. Probably because of these results, period intelligence publications (“Handbook on German Military Forces”) gave ~770 m/s as the PaK 40 APCBC muzzle velocity, although post war pubs corrected this (Department of the Army Pamphlet No. 30-4-4, “Foreign Military Weapons and Equipment (U) Vol. 1 Artillery (U) dated August of 1955-this document was originally classified).
In addition, German sources are contradictory in that the Official Firing Table document for the 75 mm KwK 40, StuK 40, and the PaK 40 dated October, 1943 cites 770 m/s on one of the APCBC tables therein, showing some confusion. (“Schusstafel fur die 7.5cm Kampfwagenkanone 40”).
The 88 mm gun (eighty-eight) was a German anti-aircraft and anti-tank artillery gun from World War II. It was widely used by Germany throughout the war, and was one of the most recognized German weapons of the war. Development of the original models led to a wide variety of guns.
The name applies to a series of guns, the first one officially called the 8,8 cm Flak 18, the improved 8,8 cm Flak 36, and later the 8,8 cm Flak 37. Flak is a contraction of German Flugzeugabwehrkanone meaning “anti-aircraft cannon”, the original purpose of the eighty-eight. In informal German use, the guns were universally known as the Acht-acht (“eight-eight”), a contraction of Acht-komma-acht Zentimeter (“8.8 cm”). In English, “flak” became a generic term for ground anti-aircraft fire.
The versatile carriage allowed the eighty-eight to be fired in a limited anti-tank mode when still on wheels, and to be completely emplaced in only two-and-a-half minutes. Its successful use as an improvised anti-tank gun led to the development of a tank gun based upon it. These related guns served as the main armament of tanks such as the Tiger I: the 8.8 cm KwK 36, with the “KwK” abbreviation standing for KampfwagenKanone (“fighting vehicle cannon”).
In addition to these Krupp’s designs, Rheinmetall created later a more powerful anti-aircraft gun, the 8,8 cm Flak 41, produced in relatively small numbers. Krupp responded with another prototype of the long-barreled 88 mm gun, which was further developed into the anti-tank and tank destroyer 8.8 cm Pak 43 gun, and turret-mounted 8.8 cm KwK 43 heavy tank gun.