7.5 cm KwK 42

7,5 cm KwK 42 (L/70)
7,5 cm Pak 42
The 7.5 cm KwK 42 L/70 on a Panther Ausf. A tank
TypeTank gun
Place of originGermany
Service history
Used byNazi Germany
WarsWorld War II
Production history
DesignerRheinmetall-Borsig AG
ManufacturerRheinmetall-Borsig AG
Unit cost12,000 Reichsmark
Produced1942-45
Specifications
Mass1,000 kg (2,204.6 lb)
Barrel length525 cm (17 ft 3 in) bore (70 calibres)
ShellFixed QF 75 × 640mm R
Shell weight7.2 kg (16 lb) armour-piercing (APCBC-HE) Pzgr 39/42
Calibre75 mm (2.95 in)
Elevation-8° to +20°
Rate of fire6-7 rounds per minute
Muzzle velocity935 m/s (3,070 ft/s)
Maximum firing range9,850 m (32,316 ft)

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.

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

Ammunition

Panzergranate 39/42 (Pzgr. 39/42)
Penetration of an armoured plate 30 degrees from vertical
Range 100 m 500 m 1000 m 1500 m 2000 m
Penetration (mm) 138 124 112 99 89
Panzergranate 40 (Hk) (Pzgr. 40/42)
Penetration of an armoured plate 30 degrees from vertical
Range 100 m 500 m 1000 m 1500 m 2000 m
Penetration (mm) 194 174 149 127 106
Sprenggranate 42 (Sprgr. 42)

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 m
Pzgr. 39/42
(APCBC)		 935 m/s
(3,070 ft/s) 		185 179 168 158 149 140 132 116 103 91
Pzgr. 40/42
(APCR)		 1,130 m/s
(3,700 ft/s)		 265 253 234 216 199 184 170 145 124 105

See also

Weapons of comparable role, performance and era

Notes

  1. ↑ US Army Technical Manual TM9-1985-3, United States Government Printing Office Washington, 1953
  2. 1 2 Jentz, Thomas L. (1997), Germanys Panther Tank: The Quest for Combat Supremacy (Hardcover ed.), Schiffer Military History, p. 125
  3. ↑ German Explosive Ordnance (Projectiles and Projectile Fuzes) - Department of the Army Technical Manual TM-9-1985-3. 1953. p. 411-412.
  4. ↑ Bird, Lorrin Rexford; Livingston, Robert D. (2001). WWII Ballistics: Armor and Gunnery. Overmatch Press. p. 61.

References