7.5 cm KwK 42

{{Short description|German tank gun}}{{Infobox weapon

|name=7,5 cm KwK 42 (L/70)
7,5 cm Pak 42

|image=Panther-Sinsheim.jpg

|caption=The 7.5 cm KwK 42 L/70 on a Panther Ausf. A tank

|origin= Germany

|type= tank gun

|is_ranged=YES

|is_bladed=

|is_explosive=

|is_artillery=YES

|is_vehicle=

|is_UK=yes

|service=

|used_by= {{Flag|Nazi Germany}}

|wars= World War II

|designer=Rheinmetall-Borsig AG

|design_date=

|manufacturer=Rheinmetall-Borsig AG

|unit_cost= 12,000 Reichsmark

|production_date=1942-45

|number=

|variants=

|weight= {{cvt|1000|kg|1|lk=on}}

|part_length=

{{cvt|525|cm|ftin}} bore (70 calibres)

|width=

|height=

|crew=

|cartridge=Fixed QF 75 × 640mm R

|cartridge_weight={{cvt|7.2|kg}} armour-piercing (APCBC-HE) Pzgr 39/42

|caliber={{cvt|75|mm|sigfig=3}}

|action=

|rate= 6 rounds per minute

|velocity= {{cvt|935|m/s}}

|range=

|max_range= {{cvt|9850|m|0}}

|feed=

|sights=

|breech=

|recoil=

|carriage=

|elevation=-8° to +20°

|traverse=

}}

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 PzGr. 39/42 was the result, and apart from the addition of wider driving bands it was otherwise identical to the older 7.5 cm PzGr. 39. The wider driving bands added a little extra weight, from 6.8 kg for the old PzGr.39, to 7.2 kg for the new PzGr.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 used: APCBC-HE, APCR and HE.

Data for KwK 42 and Pak 42

Type: Tank gun (KwK 42), Anti-tank gun (Pak 42)
Caliber: {{convert|7.5|cm|in|2|abbr=on}}
Shell: 75×640 mm R
Barrel length in calibres: 70
Barrel length: {{convert|5.250| m |ftin|abbr=on}}
Breech: semiautomatic, falling wedge
Weight with muzzle brake and breech: {{convert|1000|kg|lb|abbr=on}}
Recoil length: 400 mm (normal), 430 mm (maximum)
Maximum range: {{convert|10|km|abbr=on}} 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: {{convert|6.8|kg|lb|abbr=on}}
Explosive filler: 18 g of phlegmatized RDX
Round weight: {{convert|14.3|kg|abbr=on}}
Round length: {{convert|893.2|mm|ftin|abbr=on}}
Cartridge case length: {{convert|640|mm|ftin|abbr=on}}
Muzzle velocity: {{convert|935|m/s|abbr=on}}

class="wikitable" style="text-align:right;" \|+Penetration of an armoured plate 30 degrees from vertical{{citation\| title=Germanys Panther Tank: The Quest for Combat Supremacy \|first= Thomas L. \|last=Jentz \|publisher= Schiffer Military History \|edition=Hardcover \|date=1997 \| page = 125}}
Range \|100 m \|500 m \|1000 m \|1500 m \|2000 m
Penetration (mm) \|138 \|124 \|112 \|99 \|89

class="wikitable" style="text-align:right;"

|+Penetration of an armoured plate 30 degrees from vertical{{citation| title=Germanys Panther Tank: The Quest for Combat Supremacy |first= Thomas L. |last=Jentz |publisher= Schiffer Military History |edition=Hardcover |date=1997 | page = 125}}

Range

|100 m

|500 m

|1000 m

|1500 m

|2000 m

Penetration (mm)

|138

|124

|112

|99

|89

;Panzergranate 40 (Hk) (Pzgr. 40/42)

Type: Armour Piercing, Composite Rigid
Projectile weight: {{convert|4.75|kg|abbr=on}}
Round weight: {{convert|11.55|kg|abbr=on}}
Round length: {{convert|875.2|mm|ftin|abbr=on}}
Cartridge case length: {{convert|640|mm|ftin|abbr=on}}
Muzzle velocity: {{convert|1130|m/s|abbr=on}}

class="wikitable" style="text-align:right;" \|+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

class="wikitable" style="text-align:right;"

|+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)

Type: High explosive
Projectile weight: {{convert|5.74|kg|abbr=on}}
Explosive weight: 0.650 kg (1.66 lb) (2,720 Kilojoules)
Round weight: {{convert|11.14|kg|abbr=on}}
Round length: {{convert|929.2|mm|ftin|abbr=on}}
Cartridge case length: {{convert|640|mm|ftin|abbr=on}}
Muzzle velocity: {{convert|700|m/s|abbr=on}}

Penetration comparison

class="wikitable" style="text-align:right;" \|+Calculated penetration (90 degrees) uses American and British 50% success criteria, and allowing direct comparison to foreign gun performance.{{cite book\|last1=Bird \|first1=Lorrin Rexford\|last2=Livingston\|first2=Robert D.\|title=WWII Ballistics: Armor and Gunnery\|date=2001\|publisher=Overmatch Press\|page=61}} ! rowspan=2\|Ammunition type	rowspan=2\|Muzzle velocity (m/s)	colspan=11\|Penetration (mm)
100 m ! 250 m ! 500 m ! 750 m ! 1000 m ! 1250 m ! 1500 m ! 2000 m ! 2500 m ! 3000 m
style="text-align:center"\|Pzgr. 39/42 (APCBC) \|style="text-align:center"\|{{convert\|935\|m/s\|abbr=on}} \| 185 \| 179 \| 168 \| 158 \| 149 \| 140 \| 132 \| 116 \| 103 \| 91
style="text-align:center"\|Pzgr. 40/42 (APCR) \|style="text-align:center"\|{{convert\|1130\|m/s\|abbr=on}} \| 265 \| 253 \| 234 \| 216 \| 199 \| 184 \| 170 \| 145 \| 124 \| 105

class="wikitable" style="text-align:right;"

|+Calculated penetration (90 degrees) uses American and British 50% success criteria,
and allowing direct comparison to foreign gun performance.{{cite book|last1=Bird |first1=Lorrin Rexford|last2=Livingston|first2=Robert D.|title=WWII Ballistics: Armor and Gunnery|date=2001|publisher=Overmatch Press|page=61}}

! rowspan=2|Ammunition type

rowspan=2|Muzzle velocity
(m/s)

colspan=11|Penetration (mm)

100 m

! 250 m

! 500 m

! 750 m

! 1000 m

! 1250 m

! 1500 m

! 2000 m

! 2500 m

! 3000 m

style="text-align:center"|Pzgr. 39/42 (APCBC)

|style="text-align:center"|{{convert|935|m/s|abbr=on}}

| 185

| 179

| 168

| 158

| 149

| 140

| 132

| 116

| 103

| 91

style="text-align:center"|Pzgr. 40/42 (APCR)

|style="text-align:center"|{{convert|1130|m/s|abbr=on}}

| 265

| 253

| 234

| 216

| 199

| 184

| 170

| 145

| 124

| 105

=Weapons of comparable role, performance and era=

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 {{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}}
Penetration data extracted from a French DoD publication "Le Panther" Ministere de la Guerre, Section Technique de l'Armee, Groupement Auto-Chars, 1947.