The 3.7 cm KwK 36 L/45 (3.7 cm Kampfwagenkanone 36 L/45) was a German 3.7 cm cannon used primarily as the main armament of earlier variants of the German Sd.Kfz. 141 Panzerkampfwagen III medium tank. It was used during the Second World War.
It was essentially the 3.7 cm Pak 36 modified for use in a rotating enclosed turret.
Ammunition The 3.7 cm KwK 36 used the 37 x 249 mm. R cartridge. Average penetration performance established against rolled homogeneous steel armor plate laid back at 30° from the vertical.
PzGr.18 (Armour-piercing) Weight of projectile: Muzzle velocity: 100 m500 m1000 m1500 m2000 m34 mm29 mm23 mm19 mm --
PzGr.40 (Armour-piercing composite rigid) Weight of projectile: Muzzle velocity: 100 m500 m1000 m1500 m2000 m64 mm31 mm -- -- --
PzGr.39 - Armour-piercing
Sprgr.Patr.34 - High-explosive
+Calculated penetration (at 90 degrees) using American and British 50% success criteria,and allowing comparison to performance of other guns.Ammunition typeMuzzle velocityPenetration 100 m 500 m 1000 m 1500 m Pzgr. APHE 745 m/s Pzgr. 40 APCR1,020 m/s -- -- +Revised penetration statistics due to HE burster size, projectile weight, and possible decreases of early war metal quality. Ammunition typeMuzzle velocityPenetration 100 m 250 m 500 m 750 m 1000 m 1250 m 1500 m 1750 m 2000 m 2500 m Pzgr. APHE 745 m/s
Vehicles mounted on Leichttraktor Neubaufahrzeug Sd.Kfz. 141 Panzerkampfwagen III versions A until E (de: Ausfertigung A bis E) Sd.Kfz. 141 Panzerkampfwagen III Ausf. F (the last 100 Ausf. F mounted the 5 cm KwK 38 L/42 gun) Sd.Kfz. 141 Panzerkampfwagen III Ausf. G (the first 50 Ausf. G)
Notes 2. http://www.wehrmacht-history.com/heer/panzer-armaments/3.7-cm-kwk-36.htm