The 7.5 cm KwK 42 L/70 (from 7.5 cm Kampfwagenkanone 42 L/70) was a 7.5 cm calibre German tank gun used on German armoured fighting vehicles in the Second World War. The gun was the armament of the Panther medium tank and two variants of the Jagdpanzer IV self-propelled anti-tank gun. On the latter it was designated as the "7.5 cm Panzerabwehrkanone 42" (7.5 cm Pak 42) anti-tank gun.
Design The increased muzzle velocity and operating pressure of the new gun required a new armour-piercing projectile to be designed. The Panzergranate 39/42 was the result, and apart from the addition of a second drive band it was otherwise identical to the older 7.5 cm Panzergranate 39. The new projectile increased the weight from 6.8 kg for the old Panzergranate 39, to 7.2 kg for the new Panzergranate 39/42.US Army Technical Manual TM9-1985-3, United States Government Printing Office Washington, 1953
The gun was fired electrically, the primer being initiated using an electric current rather than a firing pin. The breech operated semi-automatically so that after the gun had fired, the empty shell casing was automatically ejected, and the falling wedge type breech block remained down so that the next round could be loaded. Once the round was loaded the breech closed automatically and the weapon was ready to be fired again. Three different types of ammunition were developed: APCBC-HE, HE, and APCR, although the latter was extremely rare in service, due to the recall of tungsten to be used in manufacturing instead.
Data for KwK 42 and Pak 42
Type: Tank gun (KwK 42), Anti-tank gun (Pak 42) Caliber: Shell: 75×640 mm R Barrel length in calibres: 70 Barrel length: Breech: semiautomatic, falling wedge Weight with muzzle brake and breech: Recoil length: 400 mm (normal), 430 mm (maximum) Maximum range: indirect Sight: TZF 12 or 12a (Panther), Sfl.ZF 1a (Jagdpanzer IV/70 (A) and (V))
Ammunition Panzergranate 39/42 (Pzgr. 39/42) Type: Armour Piercing Capped Ballistic Cap, High Explosive Projectile weight: Explosive filler: 18 g of phlegmatized RDX Round weight: Round length: Cartridge case length: Muzzle velocity:
+Penetration of an armoured plate 30 degrees from vertical Range100 m500 m1000 m1500 m2000 mPenetration (mm)1381241129989
Panzergranate 40 (Hk) (Pzgr. 40/42) Type: Armour Piercing, Composite Rigid Projectile weight: Round weight: Round length: Cartridge case length: Muzzle velocity:
+Penetration of an armoured plate 30 degrees from vertical Range100 m500 m1000 m1500 m2000 mPenetration (mm)194174149127106
Sprenggranate 42 (Sprgr. 42) Type: High explosive Projectile weight: Explosive weight: (2,720 Kilojoules) Round weight: Round length: Cartridge case length: Muzzle velocity:
Penetration comparison
+Calculated penetration (90 degrees) uses American and British 50% success criteria,and allowing direct comparison to foreign gun performance.Ammunition typeMuzzle velocityPenetration (mm) 100 m 250 m 500 m 750 m 1000 m 1250 m 1500 m 2000 m 2500 m 3000 mPzgr. 39/42 (APCBC) 185 179 168 158 149 140 132 116 103 91Pzgr. 40/42 (APCR) 265 253 234 216 199 184 170 145 124 105
See also Weapons of comparable role, performance and era British Ordnance QF 17 pounder US 76 mm gun M1 USSR D-5T 85 mm gun Japan Type 5 75 mm tank gun
Notes
References
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 Hogg, Ian V. German Artillery of World War Two. 2nd corrected edition. Mechanicsville, PA: Stackpole Books, 1997 Penetration data extracted from a French DoD publication "Le Panther" Ministere de la Guerre, Section Technique de l'Armee, Groupement Auto-Chars, 1947.
External links