7.5 cm Pak 40

7.5 cm Panzerabwehrkanone 40
A Pak 40 75 mm anti-tank gun, displayed in Parola Tank Museum, Finland
Type	Anti-tank gun
Place of origin	Nazi Germany
Service history
In service	1942–1945
Used by	Nazi Germany Finland Kingdom of Hungary Norway (postwar)
Wars	World War II
Production history
Designer	Rheinmetall
Designed	1939–1941
Manufacturer	Rheinmetall
Produced	1941–1945
No. built	Approx. 23,500
Specifications
Mass	1,425 kg (3,142 lb) (in action)
Length	6.2 m (20 ft 4 in)
Barrel length	46 calibres
Shell	75×714mmR
Caliber	75 mm (2.95 inch)
Breech	semi-automatic horizontal sliding block
Carriage	split trail
Elevation	-5° to +22°
Traverse	65°
Rate of fire	14 rounds per minute
Effective firing range	1,800 metres (5,906 ft) direct fire 7,678 metres (25,190 ft) indirect HE shell

The 7.5 cm Pak 40 (7.5 cm Panzerabwehrkanone 40) was a German 7.5 centimetre anti-tank gun developed in 1939-1941 by Rheinmetall and used during the Second World War. Pak 40 formed the backbone of German anti-tank guns for the latter part of World War II.

Development

Development of the Pak 40 began in 1939 with contracts being placed with Krupp and Rheinmetall to develop a 7.5 cm anti-tank gun. Priority of the project was initially low, but following the invasion of the USSR in 1941 and the unexpected appearance of heavily armoured Soviet tanks such as the T-34 and KV-1, it was given an increased priority. The first pre-production guns were delivered in November 1941.^{[citation needed]} In April 1942, the Wehrmacht had 44 guns in service; by 1943 the Pak 40 formed the bulk of German anti-tank artillery.

Operational use

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.

About 23,500 Pak 40s were produced, and about 6,000 more were used to arm tank destroyers. The unit manufacturing cost amounted to 2,200 man-hours at 12,000 RM. A lighter automatic version, the heaviest of the Bordkanone series of heavy calibre aircraft guns, was used as the BK 7,5 in the Henschel Hs 129B-3 ground attack aircraft and the Junkers Ju 88P-1 bomber destroyer.

7,5 cm Pak 40 in Albania in 1943

Performance

The weapon was effective against almost every Allied tank until the end of the war. The Pak 40 was much heavier than the 5 cm Pak 38; its decreased mobility meant that it was difficult or even impossible to move without an artillery tractor on boggy ground.

The Pak 40 was first used in Russia where it was needed to combat the newest Soviet tanks. It was designed to fire the same low-capacity APCBC, HE and HL projectiles which had been standardized for use in the long barreled Kampfwagenkanone KwK 40 tank-mounted guns. In addition there was an APCR shot (Panzergranate 40) for the Pak 40, a munition which - reliant on supplies of tungsten - 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 (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).^{[citation needed]} 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 (2,500 ft/s), 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.^{[citation needed]} 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.^{[citation needed]}

Pak 40 with crew on the Eastern Front in 1944

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 were apparently never a problem in the Pak version of the gun.

For unknown reasons some 75 mm APCBC cartridges appear to have been produced with a charge which gave a muzzle velocity of about 770 m/s (2,500 ft/s). The first documented firing by the US of a Pak 40 recorded an average muzzle velocity of 776 m/s for its nine most instrumented firings. Probably^{[citation needed]} because of these results, period intelligence publications ("Handbook on German Military Forces") gave about 770 m/s as the Pak 40 APCBC muzzle velocity. Post war publications corrected this.

German sources differ; the Official Firing Table document for the 75 mm KwK 40, StuK 40, and the Pak 40 dated October, 1943 gives 770 m/s on one of the APCBC tables.

General characteristics

• Caliber: 75 mm
• Barrel length: L/46
• Rifling: 32 Grooves, right-hand increasing twist, 1/24 to 1/18.
• Length with the carriage: 6.2 metres (20.3 ft)
• Length: 3.45 metres (11.3 ft)
• Width: 2 metres (6.6 ft)
• Height: 1.25 metres (4.1 ft)
• Weight (combat ready): 1,425 kilograms (3,142 lb)

German Pak 40 75 mm

• Traverse: 65°
• Elevation: -5° to + 22°
• Rate of fire: 14 rounds per minute
• Engagement range: 1,800 metres (5,906 ft)
• Indirect range: 7,678 metres (25,190 ft) m (HE shell)
• Projectile weight: 3.18 kilograms (7.0 lb) to 6.8 kilograms (15.0 lb)

Pak 40 seen from the rear

Performance

Round	Muzzle velocity	Penetration of armour 90 degrees incidence at 500 metres (1,640 ft)
Armour piercing	792 m/s (2,598 ft/s)	132 millimetres (5.2 in)
APCR	933 m/s (3,061 ft/s)	154 millimetres (6.1 in)
HE	550 m/s (1,804 ft/s)	n/a

Survivors

Pak 40s are or have been lately held in several military museums, outside museums or free entrance open-air fields

A Finnish army Pak 40 in firing position during the Continuation War

Country	Location	Place
Netherlands	Zandoerle	Centre village green
Belgium	Ostend	Atlantic Wall Open Air Museum, Raversijde
Canada	Borden, Ontario	Base Borden Military Museum
Canada	Shilo, Manitoba	The Central Museum of The Royal Regiment of Canadian Artillery
Finland	Miehikkälä, South Karelia	Salpa Line Museum
Finland	Virolahti, South Karelia	Bunker Museum
Finland	Parola, Western Finland Province	Parola Tank Museum
Finland	Mikkeli, Southern Savonia	Infantry Museum
Finland	Oulu, Northern Ostrobothnia	Northern Brigade (Pohjan prikaati) memorial area, 2 pieces
Finland	Hämeenlinna, Tavastia Proper	Artillery Museum of Finland
Finland	Hanko, Uusimaa	Hanko Front Line Museum
Finland	Helsinki	Military Museum of Finland, Suomenlinna filial
France	Saumur	Musée des Blindés or Association des Amis du Musée des Blindés
Germany	Munster	Deutsches Panzermuseum
Serbia	Belgrad	Belgrade Military Museum
Spain	El Goloso, Madrid	Museo de Unidades Acorazadas; and others
USA	Danville, Virginia	American Armoured Foundation Tank Museum
USA	Tooele, Utah	Privately owned collection
UK	Duxford	Imperial War Museum

See also

• Ordnance QF 17 pounder - similar British gun
• 3 inch Gun M5 - similar US anti-tank gun
• 7.5 cm PaK 97/38 - captured French 75 mm anti-tank gun on German carriage
• 7.5 cm PaK 41 - 75 mm anti-tank gun based on squeeze bore principle

References

Notes

Bibliography

• Engelmann, Joachim and Scheibert, Horst. Deutsche Artillerie 1934-1945: Eine Dokumentation in Text, Skizzen und Bildern: Ausrüstung, Gliederung, Ausbildung, Führung, Einsatz. Limburg/Lahn, Germany: C. A. Starke, 1974
• Gander, Terry and Chamberlain, Peter. Weapons of the Third Reich: An Encyclopedic Survey of All Small Arms, Artillery and Special Weapons of the German Land Forces 1939-1945. New York: Doubleday, 1979 ISBN 0-385-15090-3
• Hogg, Ian V. German Artillery of World War Two. 2nd corrected edition. Mechanicsville, PA: Stackpole Books, 1997 ISBN 1-85367-480-X

External links

• Intelligence report on Pak 40 at Lonesentry.com
• Panzerworld.net
• Model Book German 7,5 cm Anti-tank Gun Pak 40