8.8 cm KwK 43

The KwK 43 L/71 (Kampfwagenkanone&mdash;fighting vehicle cannon) was an 8.8 cm calibre tank gun designed by Krupp and used by the German Wehrmacht, during the Second World War. It was the primary armament of the Panzerkampfwagen VI Ausf. B Tiger II, and was the most powerful anti-tank gun to be put on a tank with a rotatable turret to reach service during World War II.

The anti-tank gun version of this weapon was known as the PaK 43. This name was also applied to versions of this weapon mounted in various armored vehicles such as the tank destroyers Jagdpanther, Hornisse/Nashorn and Ferdinand/Elefant. The Nashorn was the first vehicle to carry the KwK/PaK 43 series of guns. The series included: PaK 43 (cruciform mount), PaK 43/41 (two-wheel split-trail carriage), PaK 43/1 (Nashorn), PaK 43/2 (Ferdinand/Elefant), PaK 43/3 and 43/4 (Jagdpanther) and KwK 43 (Tiger II).

Design and development
At 6.24 m the barrel of the KwK 43 was over 1.3 meters longer than that of the 8.8 cm KwK L/56 used for the Tiger I. The cartridge was also considerably taller (at 822 mm) and wider than that of the KwK36, allowing for a much heavier propellant charge. All guns of the PaK/KwK 43 series could use the same ammunition.

KwK 43 and PaK 43's were at first manufactured with monobloc barrels, but due to the much higher muzzle velocity and operating pressures, barrel wear was an issue. As a result the design was later changed to that of a two-piece barrel. This had no effect on performance but made replacing a worn out barrel much faster and easier than before.

The massively increased operating pressures of the new gun in turn also required a new armour piercing shell to be designed, one which could better cope with these higher pressures. This was to result in the PzGr.39/43 APCBC-HE projectile, which apart from the addition of much wider driving bands was otherwise identical to the older 10.2 kilogram PzGr.39-1 APCBC-HE projectile used by the 8.8 cm KwK36 and PaK43 guns. The wider driving bands resulted in a new increased weight of 10.4 kilograms for the PzGr.39/43. However up until the full transition to the new PzGr.39/43 round was complete the older PzGr.39-1 was used for the KwK & PaK 43, but only provided the gun had been used for no more than 500 rounds. Over this, the expected barrel wear combined with the narrow driving bands could lead to a loss of pressure. The new PzGr.39/43 could be fired without loss of pressure until the barrel was worn out, thus requiring no restriction.

PzGr.39-1 FES & Al all up weight: 10.2 kg (9.87 kg without fuze & bursting charge) PzGr.39/43 FES & Al all up weight: 10.4 kg (10.06 kg without fuze & bursting charge)

The same 278 gram BdZ 5127 fuze and 59 gram Amatol bursting charge was used for both types of projectiles (PzGr.39-1 & PzGr.39/43), requiring armoured targets of 30mm or thicker to ignite after penetration for maximum behind armour effects.

PzGr. 39/43 APCBC-HE

 * Type: Armour Piercing Capped with Ballistic Cap - High Explosive
 * Projectile weight: 10.4 kg (22.92 lbs)
 * Muzzle velocity: 1,000 m/s (3,281 ft/s)

PzGr. 40/43 APCR

 * Type: Armour-piercing, Composite Rigid construction)
 * Projectile weight: 7.3 kg (16 lbs)
 * Muzzle velocity: 1,130 m/s (3,707 ft/s)

Gr. 39/3 HL (HEAT)

 * Projectile weight: 7.65 kg (17 lbs)
 * Muzzle velocity: 600 m/s (1,968 ft/s)
 * Penetration: 90 mm