The 7.5 cm KwK 40 (7.5 cm 40) was a German 75 mm

Second World War World War II or the Second World War (1 September 1939 – 2 September 1945) was a World war, global conflict between two coalitions: the Allies of World War II, Allies and the Axis powers. World War II by country, Nearly all of the wo ...

era vehicle-mounted gun, used as the primary armament of the German

Panzer IV The IV (Pz.Kpfw. IV), commonly known as the Panzer IV, is a German medium tank developed in the late 1930s and used extensively during the Second World War. Its ordnance inventory designation was Sd.Kfz. 161. The Panzer IV was the most numer ...

(F2 model onwards) medium tank and the (F model onwards) and

assault guns An assault gun (from , , meaning "assault gun") is a type of Armored fighting vehicle, armored infantry support vehicle and self-propelled artillery, mounting an infantry support gun on a protected self-propelled chassis, intended for providing ...

which were used as tank destroyers. The design of the KwK 40 was adapted from the similar towed anti-tank gun, the 7.5 cm Pak 40. It replaced the 7.5 cm KwK 37 with its 24- calibre barrel, providing a huge improvement in firepower for mid-war tank designs. It came in two versions, 43 ("L/43") and 48 ("L/48") calibres long barrels, the former used during 1942 and early 1943, and the latter after that point. Along with the Pak 40, the KwK 40/StuK 40 was the most numerous anti-tank gun of the German army, and remained an effective weapon until the war's end.

History

When mounted on a

casemate A casemate is a fortified gun emplacement or armoured structure from which guns are fired, in a fortification, warship, or armoured fighting vehicle.Webster's New Collegiate Dictionary When referring to antiquity, the term "casemate wall" ...

-armored assault gun-designated vehicle () instead of a turreted tank, the weapon was called Sturmkanone 40 (StuK 40). Both the KwK 40 and StuK 40 were developed from the towed 7.5 cm Pak 40 anti-tank gun. The length of the ammunition used was shortened to allow for easier storage of said ammunition in vehicles the KwK 40 and StuK 40 would be mounted on. The KwK 40 L/43 was mounted on the Panzer IV from April 1942 until June 1943. All 225 vehicles of the Panzer IV F2 mounted the L/43 with a ball shaped muzzle brake. About a 1,000 out of the 1,687 vehicles of the Panzer IV Ausf. G mounted the L/43 with a double baffle muzzle brake. The StuG III with the L/43 gun was designated as Ausf. F. of which only 120 were equipped with the L/43 (the remaining 246 having the longer L/48 version). All StuG III production runs through Ausf. F/8 to G mounted the longer L/48. The 780 original Jagdpanzer IV tank destroyers mounted the Pak 39 variant of the L/48 gun, the later Panzer IV/70 mounted the even longer Panther-derived StuK 42 L/70. The L/48 was 334 mm (13.1 inches) longer and slightly more powerful than the L/43. L/48 became the standard gun from June 1942 until the end of World War II. The gun was fitted with an electric firing mechanism and the breech operated semi-automatically. Only one-piece ammunition was used. *Following number of vehicles mounted L/48 version from June 1942-April 1945 **Approximately 6,000 vehicles of Ausf. G, H, J out of 8,800 Panzer IV **7,720 vehicles of StuG III Ausf. G + 246 of Ausf.F + 250 vehicles of StuG III Ausf. F/8 **All 1,139 vehicles of StuG IV **780 Jagdpanzer IV As with the 7.5 cm Pak 40, the muzzle brake of the KwK 40 and StuK 40 went through a series of design changes. Five types of muzzle brakes were used, gradually increasing the area of exposure to the blast. The designs progressed from tubular type double baffle muzzle brakes to single baffle ball shape muzzle brakes, which proved to be insufficient in reducing recoil, followed by a double flange type from May 1943. The front flange and rear disk type was used from March 1944, followed finally by the double disc type.

Ammunition

KwK 40 used shell 75×495 mm R * Pzgr. Patr. 39 KwK 40 ( Armour Piercing Capped Ballistic Cap (APCBC) High Explosive round) **Muzzle velocity: **Projectile: Panzergranate 39 (Pzgr. 39) **Projectile weight: **Explosive filler: of RDX/wax **Fuze: BdZ 5103 or BdZ 5103* base fuze **Round weight: **Cartridge case height: **Propelling charge: of Digl. R.P. G1 **Primer: electric, model C/22 or C/22 St. *Pzgr. Patr. 40 KwK 40 (Armour Piercing Composite Rigid) **Muzzle velocity: **Projectile: Panzergranate 40 **Projectile weight: **Explosive filler: none **Fuze: none **Round weight: **Cartridge case height: 495 mm **Propelling charge: of Gu. R.P. 7,7 **Primer: electric, model C/22 or C/22 St. *Gr. Patr. 38 HL/B KwK 40 (

High-explosive anti-tank High-explosive anti-tank (HEAT) is the effect of a shaped charge explosive that uses the Munroe effect to penetrate heavy armor. The warhead functions by having an explosive charge collapse a metal liner inside the warhead into a high-velocity ...

) **Muzzle velocity: **Projectile: Gr. 38 HL/B **Projectile weight: **Explosive filler: of RDX/wax **Fuze: A.Z. 38 St **Round weight: **Cartridge case height: 495 mm **Propelling charge: of Gu. Bl. P.-AO **Primer: electric, model C/22 or C/22 St. *Gr. Patr. 38 HL/C KwK 40 (High Explosive Anti-Tank) *7.5 cm Sprgr.Patr.34 KwK 40 (High Explosive) ''L/48'' **Muzzle velocity: **Projectile: Sprgr. 34 **Projectile weight: **Explosive filler: of amatol (2760 Kilojoules) **Fuze: kl. A.Z. 23 (0,15) umg. nose fuze **Round weight: **Cartridge case height: 495 mm **Propelling charge: of Gu. Bl. P.-AO **Primer: electric, model C/22 or C/22 St.

Penetration comparison

Usage of KwK or Pak/StuK variant

L/43

*Panzer IV Ausf. F2/G *Sturmgeschütz III Ausf. F StuK 40

L/48

*Panzer IV Ausf. G (Late production G's.) *Panzer IV Ausf. H/J *Sturmgeschütz III Ausf. F/8 and G StuK 40 *Jagdpanzer IV Pak 39 *Sturmgeschütz IV StuK 40

Notes

References

External links

{{WWIIGermanGuns World War II tank guns Tank guns of Germany World War II artillery of Germany 75 mm artillery Tank guns Weapons and ammunition introduced in 1942